MCPB and Salts RED
March 27, 2006
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SEPA
United States Prevention, Pesticides EPA 738-R-06-016
Environmental Protection and Toxic Substances March 2006
Agency (75O8C)
Reregistration
Eligibility Decision for
MCPB, and Salts
(Case 2365)
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Reregistration Eligibility Decision (RED)
Document for
MCPB
ListB
Case 2365
Approved by: /S/
Debra Edwards, Ph. D.
Director
Special Review and Reregistration
Division
Date: March 27, 2006
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Table of Contents
Executive Summary 7
I. Introduction 9
II. Chemical Overview 10
A. Chemical Identification 10
B. Use Profile 12
III. Summary of MCPB Risk Assessments 13
A. Human Health Risk Assessment 13
1. Toxicity 13
2. Dietary Exposure and Risk from Food and Drinking Water 16
3. Residential and Other Non-occupational Exposure and Risk 18
4. Aggregate Exposure and Risk 18
5. Occupational Exposure and Risk Assessment 18
B. Environmental Risk Assessment 20
1. Environmental Exposure 21
2. Environmental Effects (Hazard) 23
3. Ecological Risk Estimation (RQs) 27
4. Ecological Incidents 30
5. Endangered Species Concerns 30
6. Risk Characterization 31
IV. Risk Management, Reregistration, and Tolerance Reassessment Decision 32
A. Determination of Reregistration Eligibility 32
B. Public Comments and Responses 32
C. Regulatory Position 33
1. Food Quality Protection Act Findings 33
2. Tolerance Reassessment Summary 35
D. Regulatory Rationale 35
1. Human Health Risk Mitigation 36
2. Environmental Risk Mitigation 37
3. Endangered Species Considerations 37
5. Spray Drift Management 38
V. What Registrants Need to Do 38
A. Manufacturing Use Products 39
1. Additional Generic Data Requirements 39
2. Labeling for Manufacturing-Use Products 40
B. End-Use Products 40
1. Additional Product-Specific Data Requirements 40
2. Labeling for End-Use Products 40
C. Labeling Changes Summary Table 41
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MCPB Reregistration Eligibility Decision Team
Office of Pesticide Programs:
Biological and Economic Analysis Assessment
Elisa Rim
Jenna Carter
Alan Halvorson
Sunil Ratnayake
Environmental Fate and Effects Risk Assessment
Marie Janson
Ed Odenkirchen
Kevin Costello
Health Effects Risk Assessment
Elizabeth Mendez
Kit Farwell
Felecia Fort
Timothy Dole
Registration Support
Joanne Miller
Risk Management
James Parker
Demson Fuller
Thomas Brennan
Kelly Sherman
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Glossary of Terms and Abbreviations
ai Active Ingredient
ae Acid Equivalent
AR Anticipated Residue
CFR Code of Federal Regulations
cPAD Chronic Population Adjusted Dose
CSF Confidential Statement of Formula
CSFII USDA Continuing Surveys for Food Intake by Individuals
DCI Data Call-In
DEEM Dietary Exposure Evaluation Model
DFR Dislodgeable Foliar Residue
DNT Developmental Neurotoxicity
DWLOC Drinking Water Level of Comparison
EC Emulsifiable Concentrate Formulation
ED WC Estimated Drinking Water Concentration
EEC Estimated Environmental Concentration
EPA Environmental Protection Agency
EUP End-Use Product
FDA Food and Drug Administration
FIFRA Federal Insecticide, Fungicide, and Rodenticide Act
FFDCA Federal Food, Drug, and Cosmetic Act
FQPA Food Quality Protection Act
FOB Functional Observation Battery
GENEEC Tier I Surface Water Computer Model
IR Index Reservoir
LC50 Median Lethal Concentration. A statistically derived concentration of a substance that can be
expected to cause death in 50% of test animals. It is usually expressed as the weight of substance per
weight or volume of water, air or feed, e.g., mg/1, mg/kg or ppm.
LD50 Median Lethal Dose. A statistically derived single dose that can be expected to cause death in 50% of
the test animals when administered by the route indicated (oral, dermal, inhalation). It is expressed as
a weight of substance per unit weight of animal, e.g., mg/kg.
LOG Level of Concern
LOAEL Lowest Observed Adverse Effect Level
Micrograms Per Gram
Micrograms Per Liter
mg/kg/day Milligram Per Kilogram Per Day
mg/L Milligrams Per Liter
MOE Margin of Exposure
MRID Master Record Identification (number). EPA's system of recording and tracking submitted studies.
MUP Manufacturing-Use Product
NA Not Applicable
NAWQA USGS National Ambient Water Quality Assessment
NPDES National Pollutant Discharge Elimination System
NR Not Required
NOAEL No Observed Adverse Effect Level
OPP EPA Office of Pesticide Programs
OPPTS EPA Office of Prevention, Pesticides and Toxic Substances
PAD Population Adjusted Dose
PCA Percent Crop Area
PDF USDA Pesticide Data Program
PHED Pesticide Handler's Exposure Data
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PHI Preharvest Interval
ppb Parts Per Billion
PPE Personal Protective Equipment
ppm Parts Per Million
PRZM/EXAMS Tier II Surface Water Computer Model
Qi * The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer Risk Model
RAC Raw Agriculture Commodity
RED Reregistration Eligibility Decision
REI Restricted-Entry Interval
RfD Reference Dose
RQ Risk Quotient
SCI-GROW Tier I Ground Water Computer Model
SAP Science Advisory Panel
SF Safety Factor
SLN Special Local Need (Registrations Under Section 24©) of FIFRA)
TGAI Technical Grade Active Ingredient
USDA United States Department of Agriculture
UF Uncertainty Factor
WPS Worker Protection Standard
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Executive Summary
This document presents the Environmental Protection Agency's (hereafter referred to as
the Agency or EPA) decision on the reregistration eligibility of the registered uses of MCPB [4-
(2-methyl-4-chlorophenoxy) butyric acid]. MCPB is a phenoxy herbicide used for post-
emergence weed control to protect pea crops from a variety of weeds including Canadian thistle,
common lambsquarters, pigweed, smartweed, sowthistle, and morning glory.
The Agency made its reregistration eligibility determination based on the required data,
and the current guidelines for conducting acceptable studies to generate such data. Confirmatory
studies are required to fulfill some guideline data requirements. However, the Agency has found
that currently registered uses of MCPB are eligible for reregistration. There is currently one
MCPB tolerance, which is being reassessed at the current level.
Dietary Risk
Acute and chronic dietary risks for food and drinking water do not exceed the Agency's
level of concern. No mitigation is required.
Occupational Risk
Short- and intermediate-term inhalation risks to occupational handlers are below the
Agency's level of concern with baseline clothing (no respirator). Dermal risks associated with
mixing and loading for groundboom and aerial application are above the Agency's level of
concern with baseline clothing, but are below the Agency's level of concern when chemical-
resistant gloves are added. Therefore, chemical-resistant gloves will be required on all MCPB
product labels.
Residential Risk
There are no residential uses of MCPB. Thus, EPA did not conduct a residential
assessment.
Aggregate Risk.
Short-term and chronic aggregate risks posed by the use of MCPB are below EPA's level
of concern. No mitigation is required.
Cumulative Risk
EPA has not made a common mechanism of toxicity finding for MCPB, and
therefore the Agency did not conduct a cumulative assessment.
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Ecological Risk
EPA's level of concern is exceeded for acute risk to terrestrial plants, acute risk to small
birds that consume short grass, and chronic risk to mammals. EPA has determined that the
appropriate risk mitigation for environmental concerns at this time is to require medium or coarser
droplet sizes to minimize the potential for spray drift.
Endangered Species
The screening level ecological risk assessment results in a determination that the
use of MCPB will have no direct acute effects on freshwater fish, freshwater
invertebrates, and insects, and no direct chronic effects to birds. However, the Agency's
level of concern for direct acute effects to endangered and threatened birds, and
terrestrial and semi-aquatic plants, and for direct acute and chronic effects to mammals,
is exceeded for the use of MCPB. Potential risks to endangered species identified in the
Environmental Fate and Ecological Risk Assessment and reflected in this
Reregistration Eligibility Decision (RED) for MCPB are based solely on EPA's screening
level ecological risk assessment and do not constitute "may effect" findings under the
Endangered Species Act.
Next Steps
The Agency is issuing this Reregistration Eligibility Decision (RED) document for MCPB
as announced in a Notice of Availability published in the Federal Register.
In the future, EPA will issue a generic DCI for additional data necessary to confirm the
conclusions of this RED for the active ingredient MCPB. EPA will also issue a product-specific
DCI for data necessary to complete product reregistration for products containing MCPB.
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I. Introduction
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988 to
accelerate the reregistration of products with active ingredients registered prior to November 1,
1984. The amended Act calls for the development and submission of data to support the
reregistration of an active ingredient, as well as a review of all submitted data to the EPA.
Reregistration involves a thorough review of the scientific database underlying a pesticide's
registration. The purpose of the Agency's review is to reassess the potential risks arising from the
currently registered uses of the pesticide, to determine the need for additional data on health and
environmental effects, and to determine whether or not the pesticide meets the "no unreasonable
adverse effects" criteria of FIFRA.
On August 3, 1996, the Food Quality Protection Act (FQPA) was signed into law. This
Act amends FIFRA and the Federal Food Drug and Cosmetic Act (FFDCA) to require
reassessment of all existing tolerances for pesticides in food. FQPA also requires that by August
2006, EPA must review all tolerances in effect on the day before the enactment of the FQPA,
which was August 2, 1996. FQPA also amends the FFDCA to require a safety finding in tolerance
reassessment based on factors including aggregate risks from non-occupational sources of
pesticide exposure, whether there is increased susceptibility to infants and children, and the
cumulative effects of pesticides with a common mechanism of toxicity.
Unlike other pesticides for which EPA has followed a cumulative risk approach based on a
common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as to
MCPB and any other substances. For the purposes of this tolerance reassessment action,
therefore, EPA has not assumed that MCPB has a common mechanism of toxicity with other
substances. For information regarding EPA's efforts to determine which chemicals have a
common mechanism of toxicity, and to evaluate the cumulative effects of such chemicals, see the
policy statements released by EPA's Office of Pesticide Programs concerning common mechanism
determinations and procedures for cumulating effects from substances found to have a common
mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/.
EPA followed a four-phase, modified public participation process for MCPB.
Consistent with this process, EPA initiated Phase i of the process by transmitting the
human health and ecological risk
assessments to the technical registrants for a 3O-day error-correction review. In Phase
2, EPA considered the errors that were identified by the registrants and made changes
in the risk assessments as appropriate. To initiate Phase 3 of the process, EPA
published a Federal Register notice announcing the availability of the revised risk
assessments and supporting documents for a 6o-day public review and comment
period. During the 6o-day public comment period, EPA received two comments, from
the MCPB Task Force and a public citizen.
This document presents EPA's revised human health and environmental fate and effects
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risk assessment, its progress toward tolerance reassessment, and the reregistration eligibility
decision for MCPB. The document consists of six sections. Section I contains the regulatory
framework for reregistration and tolerance reassessment. Section II provides a description of the
chemical and a profile of the use and usage of the chemical. Section III provides a summary of
the human health and ecological risk assessments which have been revised based on data, public
comments, and other information received in response to the preliminary risk assessments.
Section IV presents the Agency's risk management, reregistration eligibility, and tolerance
reassessment decision. Section V summarizes any data requirements necessary to confirm the
reregistration eligibility decision as well as label changes and language necessary to implement the
risk mitigation measures outlined in Section IV. Section VI, the Appendices, provides related
information and supporting documents. The preliminary and revised risk assessment for MCPB
are available in the public docket EPA-HQ-2005-0263 located on-line in the Federal Docket
Management System (FDMS) at http://www.regulations.gov.
II. Chemical Overview
A. Chemical Identification
MCPB was first registered by EPA in 1964. Currently, there are five products containing
MCPB registered under Section 3 of FIFRA. There are two manufacturing use products (MCPB
Technical Acid and MCPB Technical Grade) and the three end-use formulations (Sodium MCPB
Herbicide, Thistrol Herbicide, and Sodium MCPB Solution). There are no Special Local Need
(SLN) registrations.
MCPB (sodium)
Chemical Name: [Sodium 4-(2-methyl-4-chlorophenoxy)buytrate]
Chemical Structure:
CAS Registry Number: 6062-26-6
OPP Chemical Code: 019202
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Case Number: 2365
Molecular Weight: 250.7 g/mol
Vapor Pressure: 4 x 10"7 (torr at 25 degrees Celsius)
Empirical Formula: CnHi2ClNaO3
Basic Manufacturers: A. H. Marks & Co. Ltd., Nufarm BV and Nufarm, Inc.
MCPB (acid)
Chemical Name: [4-(2-methyl-4-chlorophenoxy)butyric acid]
Chemical Structure:
CAS Registry Number: 94-81-5
OPP Chemical Code: 019201
Case Number: 2365
Molecular Weight: 228 6 g/mol
Vapor Pressure: 4 x 10"7 (torr at 25 degrees Celsius)
Empirical Formula: CiiHi3ClO3
Basic Manufacturers: A. H. Marks & Co. Ltd., Nufarm BV and Nufarm, Inc.
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B.
Use Profile
The following is information on the currently registered MCPB use sites and application
methods.
Type of Pesticide:
Summary of Use:
Target Organisms:
MCPB is a phenoxy herbicide produced as a sodium salt and an acid.
MCPB is registered for use on peas (both green and dry peas) before
flowering. There are no residential uses of MCPB.
Post-emergence control of Canadian thistle, buttercup, mustard, purslane,
ragweed, common lambsquarters, pigweed, smartweed, sowthistle,
morning glory and other broad leaf weeds
Use Classification: General Use
Formulation Types:
Application Methods:
Application Rates:
Use Locations:
Liquid
Methods of application include controlled droplet
applicator, high volume ground sprayer, low volume ground sprayer,
hand held sprayer, high volume spray (dilute), low volume spray
(concentrate), aerial and ground broadcast, and spot treatment.
The maximum label application rate is 1.5 pounds acid equivalent/acre (Ib
ae/A), applied once per year.
MCPB is primarily used in Delaware, Idaho, Illinois, Maine, Maryland,
Michigan, Minnesota, Montana, New Jersey, New York, Oregon,
Pennsylvania, Washington and Wisconsin.
Tolerances: There is 1 tolerance, for peas.
Annual Pounds Used: Less than 15,000 pounds per year
Percent Crop Treated
: Approximately 15 percent of green pea crops are treated with
MCPB. Less than 2.5 percent of other types of pea crops are treated
with MCPB.
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III. Summary of MCPB Risk Assessments
This section summarizes EPA's human health and ecological risk findings and
conclusions for MCPB. This information is presented in greater detail in the following
documents: "MCPB: Revised Occupational and Residential Exposure (ORE) and Risk
Assessments for the Reregistration Eligibility Decision RED Document" (Dole,
10/19/2005), "Revised Environmental Fate and Effects Division Preliminary Risk
Assessment for MCPB" (Janson, 3/07/2006) and MCPB HED Chapter of the
Reregistration Eligibility Decision (RED) Document" (Mendez, 10/24/2005).
The purpose of this section is to highlight the key features and findings of the risk
assessments in order to help the reader better understand the risk management decisions reached
by the Agency. While the risk assessments and related addenda are not included in this document,
they are available in the OPP Public Docket
http://www.regulations.gov/fdmspublic-relll/component/main (docket number EPA-HQ-OPP-
2005-0263).
A.
Human Health Risk Assessment
Although data do not support and the Agency is not assuming a common mechanism of
toxicity with other pesticides, MCPB is similar in its toxicity to the structurally related compound
MCPA. Also, there are similarities in the metabolism of MCPB and MCPA. Thus, studies from
the MCPA database were used as a surrogate for those lacking in the MCPB database.
1. Toxicity
MCPB has a low to moderate acute toxicity profile (Toxicity Category III to IV). The
acute dermal toxicity test indicated low to moderate acute toxicity (Toxicity Category III to IV).
The acute oral and inhalation toxicity studies showed moderate toxicity (Toxicity Category III).
MCPB is not a dermal sensitizer nor is it irritating to the skin. However, it does cause moderate
eye irritation. Please see Table 1, below, for the acute toxicity profile for MCPB.
Table 1. Acute Toxicity Profile for MCPB
Guideline No.
870.1100
870.1100
870.1200
870.1200
870.1300
Study Type
Acute oral - rat
Acute oral - rat
Acute dermal - rabbit
Acute dermal - rat
Acute inhalation - rat
MRID#
116340
144801
116342
144799
41630001
Results
LD50=1570mg/kg
LD50 = 4300 mg/kg
LD50>10000mg/kg
LD50 > 2000 mg/kg
LC50>1.14mg/L
Toxicity Category
III
III
IV
III
III
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Table 1. Acute Toxicity Profile for MCPB
Guideline No.
870.2400
870.2400
870.2500
870.2600
Study Type
Acute eye irritation - rabbit
Acute eye irritation - rabbit
Acute dermal irritation - rabbit
Skin sensitization - guinea pig
MRID#
116343
144797
144798
144800
Results
Moderately irritating
Moderately irritating
Non-irritating
Negative
Toxicity Category
III
III
IV
IV
Kidney and liver effects appear to be the most prevalent hazard concerns for MCPB,
based on the effects seen throughout the MCPA database. Developmental and reproductive
toxicity studies did not indicate an enhanced sensitivity or susceptibility to young animals.
Neurotoxicity effects were noted in studies conducted on MCPA. Therefore, a developmental
neurotoxicity study is required for MCPB.
EPA has established an acute reference dose (RfD) of 0.2 mg/kg/day for MCPB, based on
a No Observed Adverse Effect Level (NOAEL) of 200 mg/kg/day in an acute neurotoxicity study
of MCPA in rats. The main effect observed at the Lowest Observed Adverse Effect Level
(LOAEL) was gait impairment in male rats. The RfD was calculated by dividing the NOAEL by
an uncertainty factor of 1,000 (lOx for interspecies variability, lOx for intraspecies variability, and
lOx FQPA database uncertainty to account for the lack of a developmental neurotoxicity study).
The uncertainty factors are discussed in more detail below.
EPA has established a chronic RfD of 0.015 mg/kg/day for MCPB, based on a NOAEL of
4.4 mg/kg/day in a chronic toxicity study of MCPA in rats. Effects observed at the LOAEL were
liver and kidney toxicity. The RfD was calculated by dividing the NOAEL by an uncertainty
factor of 300 (1 Ox for interspecies variability, lOx for intraspecies variability, and 3x database
uncertainty to account for the lack of a developmental neurotoxicity study). The uncertainty
factors are discussed in more detail, below.
There were no tumor effects observed in any MCPA or MCPB studies, and therefore EPA
did not conduct a cancer assessment. Mutagenicity tests conducted with MCPB and MCPA were
negative.
FOP A Safety Factor
FQPA directs EPA, in setting pesticide tolerances, to use an additional tenfold margin of
safety to protect infants and children, taking into account the potential for pre- and post-natal
toxicity and the completeness of the toxicology and exposure databases. The statute authorizes
EPA to modify this tenfold FQPA safety factor only if reliable data demonstrate that the resulting
level of exposure will be safe for infants and children.
The toxicity database for MCPB, which is bridged from MCPA, includes acceptable
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developmental and reproductive toxicity studies. There is no evidence in the developmental
(MCPB and MCPA) or reproductive (MCPA) toxicity studies of increased sensitivity or
susceptibility to newborns. However, EPA has determined that all or part of the FQPA safety
factor must be retained to account for database uncertainties.
Neurotoxicity was not seen in the MCPB subchronic studies (clinical signs of
neurotoxicity in a rabbit developmental study occurred on the day of or day prior to death or
moribund sacrifice and were attributed to agonal death). However, neurotoxicity was noted in an
acute and subchronic MCPA rat study (decreased arousal, impaired coordination and gait,
reduced motor activity, and reduced grip strength). Given that the MCPA database was used to
evaluate MCPB, signs of neurotoxicity are expected with MCPB. A developmental neurotoxicity
study is therefore necessary to further characterize the potential for pre- and post-natal
neurotoxicity. The MCPB and MCPA databases do not include a DNT study, and therefore an
FQPA database uncertainty factor must be retained for exposure scenarios through which
exposure to children or pregnant women is expected.
The size of the FQPA database uncertainty factor is based on an analysis of DNT studies
previously submitted to the Agency which suggests that NOAELs from a DNT study could be
lower than the lowest dose tested in the studies currently used in the risk assessment. For MCPB,
a lOx FQPA database uncertainty factor is retained for the acute dietary risk assessment because
it is anticipated that the DNT may yield a NOAEL approximately ten times lower than the one
currently used for the risk assessment. A 3x FQPA database uncertainty factor is retained for the
chronic dietary risk assessment because it is expected that the DNT could yield a NOAEL
approximately three times lower than the one currently used for this risk assessment.
The toxicological endpoints and uncertainty factors used in the human health risk
assessment for MCPB are listed below in Table 2.
Table 2. Summary of Toxicological Doses and Endpoints for the MCPB Dietary Risk Assessment
Exposure
Scenario
Acute Dietary
(general
population)
Chronic
Dietary
(general
population)
Dose
(mg/kg/day)
NOAEL = 200
mg/kg/day
NOAEL= 4.4
mg/kg/day
Endpoint
Clinical signs
of
neurotoxicity
Hepatotoxicity
and
nephrotoxicity
Study
Acute neurotoxicity
study (MCPA) in rats
withaLOAELof400
mg/kg/day based on
gait impairment in
males
[MRID No.
43562602]
Chronic toxicity study
(MCPA) in rats with a
LOAELofl7.6
mg/kg/day
[MRID No.
Uncertainty
Factor
lOOx
(1 Ox for
intraspecies
variation and
1 Ox for
interspecies
extrapolation)
lOOx
(1 Ox for
intraspecies
variation and
1 Ox for
FQPA
Safety
Factor
lOx
(for database
uncertainty)
3x
(for database
uncertainly)
PAD
(mg/kg/day
)
0.2
0.015
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Table 2. Summary of Toxicological Doses and Endpoints for the MCPB Dietary Risk Assessment
Exposure
Scenario
Cancer
Dose
(mg/kg/day)
Endpoint
Study
40634101]
Uncertainty
Factor
interspecies
extrapolation)
FQPA
Safety
Factor
PAD
(mg/kg/day
)
Classification: Not likely to be carcinogenic to humans
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2. Dietary Exposure and Risk from Food and Drinking Water
EPA conducted acute and chronic dietary (food and drinking water) risk assessments for
MCPB using the Dietary Exposure Evaluation Model software with the Food Commodity Intake
Database (DEEM-FCID™, Version 2.03). To conduct the assessments, both food consumption
data from USDA's Continuing Survey of Food Intakes by Individuals (CSFII), 1994-1996 and
1998, and screening-level model results for drinking water exposure were incorporated in the
DEEM-FCID™ to estimate combined food and drinking water dietary risks.
a. Dietary Exposure and Risk from Food
The acute and chronic dietary (food only) risk assessments assumed 100% crop treated
and tolerance-level residues for all commodities. This analysis is known as an unrefined (Tier 1)
assessment, which provides an upper-bound estimate of potential risks.
The results of the dietary (food only) exposure and risk estimates for MCPB for the
general population and the most highly-exposed population subgroup (all infants <1 year old) are
summarized below in Table 3. The acute assessment shows that at the 95th percentile of
exposure, the risk estimates are below the Agency's level of concern (<100% acute Population
Adjusted Dose [aPAD]) for the general U.S. population and all population subgroups. The most
highly exposed population subgroup was infants (<1 years old) at 2% of the aPAD. Note that for
MCPB and other pesticides for which EPA conducts an unrefined Tier 1 analysis, the Agency
presents acute dietary exposure results at the 95th percentile of exposure, which provides a more
realistic though still high-end estimate of risk. The chronic risk estimates were also below the
Agency's level of concern (<100% of the chronic Population Adjusted Dose [cPAD]) for the
general U.S. population and all population subgroups. The most highly exposed population
subgroup was infants (<1 years old) at <4% of the cPAD.
Table 3. Summary of dietary (food only) exposure and risk for MCPB
Population Subgroup
General U.S. Population
All Infants (< 1 yr)
(S
aPAD
(mg/kg/day)
0.2
0.2
4cute Dietary
5th Percentile)
Exposure
(mg/kg/day)
0.000754
0.003971
%
aPAD*
0.4
2
C
cPAD
(mg/kg/day)
0.015
0.015
[ironic Dietary
Exposure,
mg/kg/day
0.000128
0.000568
% cPAD*
0.9
3.8
* Risks > 100% of the aPAD or cPAD exceed EPA's level of concern.
b. Dietary Exposure from Drinking Water
Drinking water exposure to pesticides can occur through surface and ground water
contamination. EPA considers acute (one day) and chronic (lifetime) drinking water risks and
uses modeling (or monitoring data, if available and of sufficient quality) to estimate those
exposures. For MCPB, EPA used modeling to calculate Estimated Drinking Water
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Concentrations (EDWCs) for groundwater and surface water sources of drinking water for use in
the human health risk assessment.
EPA used the Tier II screening model, Pesticide Root Zone Model and Exposure Analysis
Modeling System (PRZM-EXAMS), to estimate MCPB residues in surface water. The Agency
assumed MCPB would be applied once a year at 1.5 pounds of acid equivalent per acre (Ib ae/A).
EPA used the Tier I Screening Concentrations in Ground Water (SCI-GROW) model to estimate
MCPB concentrations in ground water, assuming a maximum seasonal use rate of 1.5 Ib ae/A.
The EDWCs in surface water and ground water for MCPB are provided below, in Table 4. EPA
used these EDWCs for the aggregate (food + water) risk assessments.
Table 4. Surface and Ground Water EDWCs for MCPB
Exposure Duration
Acute
Chronic (non-cancer)
Surface Water Concentration a
(ppb)
54.7
13.5
Ground Water Concentration b
(Ppb)
0.86
0.86
a From the Tier II PRZM-EXAMS - Index Reservoir model. Input parameters are based on use of MCPB on pea
crops once a year at the rate of 1.5 Ibs ae/A.
b From the SCI-GROW model assuming a maximum seasonal use rate of 1.5 Ibs ae/A
c. Dietary Exposure and Risk from Food and Drinking Water
MCPB concentrations are predicted to be higher in surface water than in ground water,
and therefore EPA used the surface water EDWCs to calculate exposure and risk from combined
dietary exposures from food and drinking water. The results of the acute and chronic dietary
exposure analyses are summarized in Table 5, below.
At the 95th percentile of exposure, the acute risk estimates are below the Agency's level of
concern (<100% aPAD) for the general U.S. population and all population subgroups. The most
highly exposed population subgroup was infants (<1 years old) at approximately 6% of the aPAD.
The chronic risk estimates were also below the Agency's level of concern (<100% cPAD) for the
general U.S. population and all population subgroups. The highest exposed population subgroup
was infants (<1 years old) at 10% of the cPAD.
Table 5. Acute and Chronic Dietary (food plus drinking water from surface water sources) Exposure and
Risk Estimates for MCPB
Population Subgroup
General U.S. Population
Acute (95th Percentile)
Exposure
(mg/kg/day)
0.003356
% aPAD*
1.7
Chronic
Exposure
(mg/kg/day)
0.00041
% cPAD*
2.8
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Table 5. Acute and Chronic Dietary (food plus drinking water from surface water sources) Exposure and
Risk Estimates for MCPB
All Infants (< 1 year old)
0.011869
5.9
0.001501
10
* Risks > 100% of the aPAD or cPAD exceed EPA's level of concern.
3. Residential and Other Non-Occupational Exposure and Risk
There are no residential uses of MCPB, and therefore EPA did not conduct a residential
risk assessment.
4. Aggregate Exposure and Risk
The FQPA amendments to the FFDCA (Section 408(b)(2)(A)(ii)) require "that there is a
reasonable certainty that no harm will result from aggregate exposure to pesticide chemical
residue, including all anticipated dietary exposures and all other exposures for which there is
reliable information." Aggregate exposure will typically include exposures from food, drinking
water, residential uses of a pesticide, and other non-occupational sources of exposure. In the case
of MCPB, the aggregate risk estimates are the same as those presented in the dietary (combined
food and drinking water) risk section of this document (see Table 5), because there are no
registered residential uses and no residential exposures are expected to occur.
While the Agency has concluded that MCPB converts to MCPA in the
environment, and that MCPA may be present in crops, residues of MCPA resulting from
MCPB use are expected to be negligible, and significantly below analytical method limits
of detection. These residues will not contribute significantly to the aggregate exposure
to MCPA from other sources, and therefore EPA did not conduct an aggregate
assessment combining MCPA exposures from MCPA and MCPB uses.
5. Occupational Exposure and Risk Assessment
Workers may be exposed to MCPB while handling, mixing, loading, or applying MCPB,
and when entering treated sites. Handler and worker risks are measured by a Margin of Exposure
(MOE) which determines how close the occupational exposure comes to a No Observed Adverse
Effect Level (NOAEL) taken from animal studies. Generally, MOEs greater than 100 do not
exceed the Agency's level of concern.
For MCPB, only short- and intermediate-term occupational exposures are expected based
on label-specified use patterns. The Agency determined that pesticide handlers and applicators
are likely to be exposed during MCPB use resulting in short- (one day to one month) and
intermediate-term (one to six month) exposures. Chronic exposures (longer than six months) are
not expected because MCPB is used only once a year.
20
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For the occupational assessment, the short- and intermediate-term dermal endpoint was
selected from an MCPA 21-day dermal toxicity study in rabbits. The short- and intermediate-
term inhalation endpoint was selected from an MCPB developmental toxicity in rabbits. Table 6,
below, provides a listing of the toxicological endpoints used in the MCPB occupational risk
assessment.
21
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Table 6. MCPB Toxicological Endpoints Used for Occupational Risk Assessment
Exposure
Scenario
Dermal (Short-
and
Intermediate-
term)
Inhalation
(Short- and
Intermediate-
Term)
Dose
(mg/kg/day)
Dermal
NOAEL=100
mg/kg/day
Oral
NOAEL = 5
mg/kg/day*
Endpoint
Kidney toxicity
and decreased
body weight gain
Study
2 1 -day dermal toxicity
study (MCPA) in rats
with a LOAEL of 1,000
mg/kg/day
[MRID No. 42715001]
Uncertainty Factor
lOOx
(lOx for intraspecies
variation and 1 Ox for
interspecies extrapolation)
Developmental toxicity
study in rabbits 1 OOx
(MCPB) with a LOAEL (lOx for intraspecies
Maternal of 20 mg/kg/day variation and 1 Ox for
mortality [MRID No. 40865401] interspecies extrapolation)
Level of
Concern
100
100
* Inhalation absorption is assumed to be equivalent to oral absorption (100 percent default value).
a.
Short- and Intermediate-Term Handler Risk
EPA has determined that there are potential short- and intermediate-term exposures to
workers who handle MCPB. The four major occupational handler exposure scenarios are as
follows:
2. Mixing/loading liquid formulations;
3. Performing aerial applications;
4. Performing groundboom applications; and
5. Flagging for aerial applications.
For MCPB, the target MOE for occupational exposures is 100, which includes the default
uncertainty factors for interspecies extrapolation and intraspecies variation. The MOEs for
handlers are summarized in Table 7. All of the MOEs for dermal exposure are greater than 100
(and therefore do not exceed the Agency's level of concern) if single layer PPE (i.e., baseline
clothing with chemical resistant gloves) is worn. All inhalation MOEs are greater than 100 at
baseline (i.e., respirators not needed), and therefore do not exceed the Agency's level of concern.
Table 7. MCPB MOEs for Handlers
Exposure Scenario
Mixing and Loading Liquids for
Aerial Application
Mixing and Loading Liquids for
Groundboom Application
Application Rate
(Ib ae/acre)
1.5
1.5
Acres/Day
350
200
Dermal MOE
(Single Layer
PPE)
580
1000
Inhalation MOE
(Baseline)
560
970
22
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Table 7. MCPB MOEs for Handlers
Exposure Scenario
Applying Aerially
Applying via Groundboom
Equipment
Flagging for Aerial Applications
Application Rate
(Ib ae/acre)
1.5
1.5
1.5
Acres/Day
350
200
350
Dermal MOE
(Single Layer
PPE)
N/A
1700
1100
Inhalation MOE
(Baseline)
9800
1600
1900
b. Short- and Intermediate-Term Postapplication Risk
Post-application exposures to MCPB can occur when workers enter pea fields recently
treated with MCPB to conduct tasks such as scouting and irrigation.
Since no chemical-specific data were available for MCPB, standard values and
assumptions were used to evaluate post-application risks (e.g., maximum application rates, default
dislodgeable foliar residue value of 20 percent).
A summary of worker risks for post-application exposures is presented in Table 8. All of
the MOEs are above 100 on Day 0 (12 hours after application) for all activities which indicates
that the risks are below the Agency's level of concern.
Table 8. MCPB Post-Application Worker Risks
Crop
Peas
Application Rate
(Ib ae/acre)
1.5
Task
Irrigation, scouting, immature plants
Transfer
Coefficient
(cnrVhr)
100
DayO
Dermal
MOE
2600
B.
Environmental Risk Assessment
A summary of the Agency's environmental risk assessment for MCPB is
presented below. The complete environmental risk assessment may be accessed in the
OPP Public Docket (EPA-HQ-OPP-2OO5-O263) at www.regulations.gov and on the
Agency's website at www.epa.gov/pesticides/reregistration/status.htm.
MCPB is a phenoxy herbicide that disrupts hormone (auxin) and protein synthesis within
various sites in sensitive plants to cause growth abnormalities in addition to non-lethal effects
(such as brown leaf tips, necrosis, decrease in size, leaf curling, chlorosis, and stem tumors). The
use of MCPB produces potential risks to non-target plants within close proximity to target areas
23
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and along streams and/or ponds near sprayed fields.
The environmental fate database is sufficient to characterize the environmental
exposure associated with MCPB use. However, EPA does intend to issue a DCI as part
of this RED to require submission of additional data for the parent compound to
address areas of uncertainty. Studies on environmental fate, aquatic invertebrates, and
marine/estuarine fish will help provide the Agency with data to refine the
environmental risk assessments and to confirm the conclusions reached in this RED.
As previously discussed, MCPB has similiar effects as MCPA. Therefore, EPA took into
consideration both MCPB and MCPA data for the purpose of this environmental assessment.
1. Environmental Exposure
a. Environmental Fate and Transport
MCPA and the CHPA-hexose conjugate are byproducts of MCPB detected in fate studies.
MCPA, MCPB, and the CHPA-hexose conjugate have similar fate characteristics as evidenced by
fate studies and chemical structure. The inclusion or exclusion of these metabolites had little
influence on the overall risk assessment because of their relatively minor presence and lack of
persistence. However, the Agency has included both metabolites in combination with parent
MCPB as total toxic residues with a combined half-life of 26 days. The Agency assumed that the
toxicity and environmental fate properties for the two metabolites are equivalent to parent MCPB.
Based on laboratory studies and physicochemical properties, MCPB is not volatile, not
persistent, and not likely to bioconcentrate. Its acidic/anionic nature, physicochemical properties,
and relatively low sorption to soil (average soil sorption coefficient of 0.85 mL/g) indicate that
MCPB is prone to leaching and runoff.
MCPB is essentially stable to hydrolysis, but photolyzed in laboratory water under optimal
light exposure conditions with half-lives of approximately 2 to 3 days. Phototransformation
products included 4 -(4-hydroxy-o-tolyloxy)butyric acid, 2,4-dihyroxyphenyl formate, o-cresol,
benzoic acid, and 2-hydroxyphenyl formate. Specific study information is not available
concerning the fate of these products, and the Agency has not included any potential effects of
aqueous photolysis products in the risk assessment based on their expected toxicity and
persistence.
b. Aquatic Organism Exposure
EPA used the PRZM 3.12 and EXAMS 2.98 models in tandem to estimate aquatic
exposure concentrations for MCPB. PRZM/EXAMS is a Tier II screening model
designed to estimate pesticide concentrations found in water at the edge of a treated
field. As such, it provides high-end values of the pesticide concentrations that might be
found in ecologically sensitive environments following pesticide application. The acute
risk assessments were performed using 1-in-10-year peak estimated environmental concentration
24
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(EEC) values for single applications of MCPB. EPA performed chronic risk assessments for
aquatic invertebrates and fish using the average 21-day and 60-day EECs, respectively.
To simulate field application of MCPB to peas, EPA selected a California lettuce
scenario and an Oregon snap bean scenario based on similarity in agricultural practices and
usage areas. The EECs from the two scenarios are provided in Table 9. The Oregon scenario
represents the typical use of MCPB application to peas, and the California scenario represents a
reasonable upper bound estimate.
Table 9. Estimated Environmental Concentrations (fig ae/L) of MCPB + Metabolites (MCPA and
CHPA/CHPA-hexose) in Surface Water (PRZM-EXAMS)
Simulation Scenario
Crop and Location
Lettuce (CA)
(Surrogate for Peas)
Snap Beans (OR)
(Surrogate for Peas)
Rate
1.5 Ibs ae/acre
(1.68kgae/ha)
1.5 Ibs ae/acre
(1.68kgae/ha)
Application
Method
Ground spray
Aerial spray
Ground spray
Aerial spray
Concentration (ug ae/L)
Peak
40.4
43.2
29.5
33.1
21-Day
Average
39.0
41.7
29.0
32.5
60-Day
Average
36.4
38.9
28.1
31.5
Surface water and groundwater monitoring data were not available for evaluation in this
risk assessment.
c. Terrestrial Organism Exposure
(i) Exposure to Terrestrial Birds and Mammals
EPA estimated exposure to birds and mammals by first predicting the amount of
MCPB residues found on animal food items, and then using information on typical food
consumption by various species of birds and mammals to determine the amount of
pesticide consumed. The amount of residues on animal feed items are based on the
Fletcher nomogram, which is a model developed by Hoerger and Kenaga (1972) and
modified by Fletcher (1994), and the current maximum application rate for MCPB (1.5
Ib ae/acre).
EPA used the terrestrial exposure (T-REX) model Ver. 1.1 to predict mean EECs
from a single application of MCPB. The predicted EECs are provided in Table 10, below.
EPA calculated acute and chronic RQs using these EECs and appropriate toxicity data.
Table 10. Mean EECs on Terrestrial Food Items from Use of MCPB on Peas
Simulation Scenario
Concentration (ppm ae)
Crop
Food item
Mean
25
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Table 10. Mean EECs on Terrestrial Food Items from Use of MCPB on Peas
Simulation Scenario
Crop
Peas
Food item
Short Grass
Tall Grass
Broadleaf Plants/Small Insects
Fruits/Pods/Seeds/Large Insects
Concentration (ppm ae)
Mean
127-5
54
67-5
10.5
(2) Exposure to Non-target Insects
There is a potential for exposure to non-target insects as a result of spray drift
from aerial and ground applications of the liquid formulation.
(3) Exposure to Non-target Terrestrial Plants
Exposure to non-target terrestrial plants is most likely to occur as a result of
spray drift from aerial and ground applications of the liquid formulation. Spray drift is
an important factor in characterizing the risk of MCPB to non-target plants. EPA used
the TerrPlant model (Ver.i.o) to predict EECs for terrestrial plants located adjacent to
the treated field. MCPB applied according to label directions as a liquid for ground or
aerial applications may impact non-target plants for some distance from the application
site depending on droplet size, wind speed, and other factors. In addition, the Agency
used the AgDrift model (Ver. 2.0.1) to estimate drift dispersion and deposition as a
result of ground and aerial spray droplet and nozzle size, wind speed, and distance from
the treated field.
2. Environmental Effects (Hazard)
a. Toxicity to Aquatic Organisms
(i) Freshwater and Estuarine/Marine Fish
Available acute toxicity data, listed below in Table 11, indicate that MCPB is
slightly to moderately toxic to freshwater fish. The median lethal concentration (LC50)
value from the rainbow trout study (the more sensitive species) was used to evaluate
acute risk to freshwater fish.
Table 11. Freshwater Fish Acute Toxicity for MCPB Sodium
26
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Species
Bluegill sunfish (Lepomis macrochirus)
Rainbow trout (Oncorhynchus mykiss)
96-hour
(mg ae/L)
(nominal
12.7
3-9
Toxicity Category
Slightly toxic
Moderately toxic
MRID Number
42532601
42532608
No chronic data for freshwater fish are available. These studies were not
previously required by the Agency.
No acute or chronic data for estuarine/marine fish are available. These studies
were not previously required by the Agency. A study with the degradate MCPA
indicates that MCPA is practically non-toxic to estuarine/marine fish for acute exposures.
However, a comparison between freshwater fish acute exposure studies with MCPB and
MCPA indicates that MCPB is potentially more toxic to fish than MCPA.
(2) Freshwater and Estuarine/Marine Invertebrates
A toxicity study with the test species Daphnia magna demonstrated that MCPB
is slightly toxic to freshwater invertebrates under acute exposure. The study results are
provided below, in Table 12.
Table 12. Freshwater Invertebrate Acute Toxicity for MCPB Sodium
Species
Waterflea
(Daphnia magna)
48-hour EC50
(mg ae/L)
50
Toxicity category
Slightly toxic
MRID Number
42532602
No freshwater aquatic invertebrate life-cycle studies or estuarine/marine
invertebrate toxicity studies are available. These studies were not previously required
by the Agency.
Studies with the degradate MCPA indicate that MCPA is practically non-toxic to
freshwater and estuarine/marine invertebrates. However, a comparison between
freshwater invertebrate acute exposure studies with MCPB and MCPA indicates that
MCPB is potentially more toxic to aquatic invertebrates than MCPA.
(3) Aquatic Plants
EPA has reviewed several aquatic plant toxicity studies to establish the toxicity of
MCPB to aquatic plants. The results of these studies are provided in Table 13, below.
27
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Table 13. Non-target Aquatic Plant Toxicity for MCPB
Species
[Study Type]
Duckweed
(Lemna gibba) [Tier I]
Green Algae
(Selenastrwn capricornutum)
[Tier I]
Blue-green Algae
(Anabaenaflos-aquae)
[Tier I]
Diatom
(Navicula pelliculosa)
[Tier I & II]
Diatom
(Skeletonema costatum)
[Tier I & II]
EC5o/NOEC
(mg ae/L)
0.21/<0.01
1-55/0.15
o.38/i.9/i-9
0.65/0.044
1.36/0.10
Endpoints Affected
Frond production
Frond biomass
Cell density
Cell density
Cell density
Cell density
MRID Number
42532604
42532605
42532603
42532609
42532606
b. Toxicity to Terrestrial Organisms
(i) Birds
MCPB is classified as moderately toxic to birds on an acute oral basis, based on a
gavage study with bobwhite quail with a median lethal dose (LD50) of 257 mg ae/kg.
MCPB is classified as practically non-toxic to avian species on an acute dietary basis,
based on an 8-day acute dietary LD50 of greater than 4,550 ppm ae for both mallard
duck and bobwhite quail. Table 14, below, summarizes the data that support the acute
toxicity endpoints used in assessing acute risks to birds.
Table 14. Avian Toxicity Studies for MCPB
Acute Oral Gavage
Species
Northern bobwhite quail (Colinus
virginianus)
LD50 (mg ae/kg)
257
Toxicity
Category
Moderately toxic
MRID No.
42560801
Acute Dietary
Species
Northern bobwhite quail (Colinus
virginianus)
8-Day LD50 (ppm
ae)
> 4,550
Toxicity
Category
Practically non-
toxic
Practically non-
MRID No.
42560802
28
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Acute Dietary
Species
Mallard duck (Anas platyrhynchos)
8-Day LD50 (ppm
ae)
> 4,550
Toxicity
Category
toxic
MRID No.
42560803
No chronic avian data on MCPB are available. These data were not previously
required by the Agency. A chronic avian reproduction study with the degradate MCPA
resulted in a no observed adverse effect concentration (NOAEC) of 1,000 mg ae/kg-diet (the
highest dose tested). No negative effects were observed in that study. EPA used the MCPA
chronic avian study to estimate chronic avian risks from MCPB. The MCPA study is an
appropriate surrogate because MCPB is expected to rapidly dissociate to MCPA in a bird's gut
due to the chemical properties of MCPB. Further, a comparison of the MCPB and MCPA avian
acute toxicity studies with bobwhite quail indicates that the two compounds have an
approximately equivalent acute toxic potential to birds.
(2) Mammals
MCPB is classified as slightly toxic to practically non-toxic to small mammals on
an acute oral basis (LD50 values range from 912 to 7,400 mg ai/kg/day). However,
adverse effects were demonstrated in the mammalian subchronic and developmental
toxicity studies. See Table 15, below, for a summary of the data.
Table 15
Species
Rat
Rabbit
. Summary of Mammalian Toxicity Endpoints for MCPB
Purity
Technic
al
97.6%
Test Type
Acute oral
Developmental
Dose
LD50 = 912-2700 mg/kg/day (males)
LD50 = 969-2981 mg/kg/day
(females)
NOAEL = 5 mg/kg/day
LOAEL = 20 mg/kg/day
Affected
Endpoints
Mortality
Maternal
toxicity;
developmental
effects
MRID
No.
116340
4086540
i
(3) Non-Target Insects
There is a potential for exposure to non-target insects from the use of MCPB. In
particular, MCPB's foliar application will result in honey bee exposure. Available data
from a honey bee acute toxicity study indicated that technical MCPB is practically non-
toxic to the honeybee (with an LD50 greater than 23 micrograms per bee).
29
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(4) Non-target Terrestrial Plants
MCPB is an herbicide, and therefore plant toxicity is expected. Terrestrial plant
toxicity studies indicate that the most sensitive monocot species in seedling emergence
tests is the onion with the lowest EC25 of 0.02 Ib ae/acre based on shoot length. This
value represents 0.093% of the maximum application rate for MCPB. The most
sensitive dicot species is cabbage with an EC25 of 0.016 Ib ae/acre in the seedling
emergence study based on shoot length. The most sensitive monocot in the vegetative
vigor test is onion, with an EC25 of 0.016 Ib ae/acre based on shoot weight. The most
sensitive dicot species in the seedling emergence study is tomato with an extrapolated
EC25 of 0.0017 Ib ae/acre based on shoot weight. The observed non-lethal effects
included brown leaf tips in cabbage, corn, onion, ryegrass, radish, and soybean; necrosis
in corn, radish, onion, and soybean; chlorosis in onion, cucumber, and lettuce; stem
tumors in soybean and tomato; leaf curl in tomato, and decreased size in cabbage,
cucumber, lettuce, onion, and ryegrass.
30
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3. Ecological Risk Estimation (RQs)
The Agency's ecological risk assessment compares toxicity endpoints from
ecological toxicity studies to EECs which are based on environmental fate
characteristics and pesticide use data. To evaluate the potential risk to non-target
organisms from the use of MCPB products, the Agency calculates a Risk Quotient (RQ),
which is the ratio of the EEC to the most sensitive toxicity endpoint values, such as the
median lethal dose (LD50) or the median lethal concentration (LC50). These RQ values
are then compared to the Agency's levels of concern (LOCs), shown in Table 16, which
indicate whether a pesticide, when used as directed, has the potential to cause adverse
effects to non-target organisms. When the RQ exceeds the LOG for a particular
category, the Agency presumes a risk of concern to that category. These risks of concern
may be addressed by further refinements of the risk assessment or mitigation. Use,
toxicity, fate, and exposure are considered when characterizing the risk, as well as the
levels of certainty and uncertainty in the assessment. EPA further characterizes
ecological risk based on any reported incidents to non-target terrestrial or aquatic
organisms in the field (e.g., fish or bird kills).
Table 16. EPA's Levels of Concern and Associated Risk Presumptions
Risk Presumption
Acute Risk - there is potential for acute risk; regulatory
action may be warranted.
Acute Endangered Species - endangered species may be
adversely affected; regulatory action may be warranted.
Chronic Risk - there is potential for chronic risk; regulatory
action may be warranted.
LOCfor
Terrestrial
Animals
0.5
0.1
i
LOCfor
Aquatic
Animals
0.5
0.05
i
LOC for
Plants
i
i
N/A
a. Risk to Aquatic Organisms
(i) Fish and Aquatic Invertebrates
No acute risks are predicted for freshwater fish and invertebrates at the
maximum predicted estimated concentration of MCPB in water bodies. All acute
freshwater fish and invertebrate RQs are less than o.oi.
There are no LOC exceedences for acute risks to estuarine/marine fish and
chronic risks to freshwater fish, freshwater invertebrates, and estuarine/marine fish for
MCPB based on RQ values calculated using acute-to-chronic ratios derived from MCPA
data.
31
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32
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(2) Aquatic Plants
For MCPB acid runoff/drift, there are no exceedances of the acute risk LOCs for
the pea scenarios that were modeled. The RQs range from 0.08 to 0.21.
b. Risk to Non-target Terrestrial Organisms
(i) Birds
Assuming mean predicted residues at the maximum application rate (1.5 Ib
ae/A), there are potential acute risks to small (20 gram) birds that consume short grass
(RQ is 0.80). All other avian RQs are below the Agency's level of concern. The avian
acute risk quotients are presented in Table 17, below.
No chronic avian risks are predicted for MCPB. Chronic RQs for MCPB were
calculated using the NOEC of 1,000 mg/kg-diet from an MCPA avian reproduction
study. The chronic RQs range from 0.02 to 0.36, which is below EPA's level of concern.
Table 17. Avian Acute Risk Quotients (RQs)
Food type
short grass
tall grass
broadleaf forage, small insects
fruit, pods, seeds,
large insects
Weight class (g)
20
1OO
1000
2O
100
1OOO
20
1OO
1000
20
100
1OOO
RQs at Predicted Mean
Residues
0.8
0.36
0.11
0-34
0.15
0.05
0.42
0.19
0.06
0.07
0.03
O.Ol
(2) Mammals
Assuming mean residue levels at the maximum MCPB application rate of 1.5 Ib
ae/A, there are no exceedances of any acute LOCs for mammals (RQs range from
-------
consume grasses, broadleaf forage, and small insects (RQs range from 1.23 to 6.44).
Table 18, below, provides the mammalian chronic RQs.
Table 18. Mammalian Chronic Risk Quotients (RQs) based on NOAEC of 91.2 mg/kg-diet
Food type Weight class (g)
RQs at Predicted Mean
Residues
Short grass
35
1OOO
6.44
5-53
2.91
Tall grass
35
1000
2-73
2-34
1.23
Broadleaf forage, small insects
35
1OOO
3.41
2.93
1.54
Fruit, large insects
35
100
0-53
0.46
0.24
Seeds, pods
35
1000
0.12
0.1
0.08
(3) Non-Target Insects
EPA does not currently quantify risks to terrestrial non-target insects. RQs are
therefore not calculated for these organisms. Since MCPB is practically non-toxic to
bees on a contact exposure basis (LD50 of >23 jag/bee), the potential for MCPB to have
adverse effects on pollinators and other beneficial insects is low.
(4) Non-Target Terrestrial Plants
EPA used the most sensitive seedling emergence values (0.02 and 0.016 Ib
ae/acre, respectively) for monocots and dicots, to calculate RQs for exposure to
terrestrial plants near MCPB-treated fields. Exposure is expected due to runoff and
spray drift. The acute LOCs for non-target terrestrial plants are exceeded for non-
endangered monocots and dicots in dryland and semi-aquatic areas located near treated
areas. Acute LOCs are also exceeded for monocots and dicots due to exposure from
spray drift. Table 19, below, provides the terrestrial plant risk quotients.
34
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Table 19. Terrestrial Plant Risk Quotients (RQs)
Scenario
Acute Non-Endangered RQs
Adjacent
to
treated
sites
Semi-
Aquatic
areas
Drift
Acute Endangered RQs
Adjacent
to
treated
sites
Semi-
Aquatic
areas
Drift
Ground spray application (1.5 Ibs ae/acre)
Monocot
Dicot
4-50
5-63
38.25
47-81
0.94
2.08
9.00
9.00
76.50
76.50
-
-
Aerial spray application (1.5 Ibs ae/acre)
Monocot
Dicot
6.00
7-50
26.25
32.81
4.69
10.42
12.00
12.00
52.50
52.50
-
-
4. Ecological Incidents
The Agency has not received any ecological incident reports for MCPB.
5. Endangered Species Concerns
The screening level ecological risk assessment results in a determination that the
use of MCPB will have no direct acute effects on freshwater fish, freshwater
invertebrates, and insects, and no direct chronic effect to birds. However, the Agency's
level of concern for direct acute effects to endangered and threatened birds, and
terrestrial and semi-aquatic plants, and for direct acute and chronic effects to mammals,
is exceeded for the use of MCPB. Further, potential indirect effects to any species
dependent upon a species that experiences effects from use of MCPB can not be
precluded based on the screening level ecological risk assessment.
a. Risk to Endangered Species
The screening level risk assessment for listed species indicates that MCPB
exceeds the acute endangered species LOCs for birds that feed on grasses, broadleaf
forage, and small insects (RQs range up to 2.26 at maximum predicted residues) and
terrestrial and semi-aquatic plants (RQs range up to 77). Also, the chronic LOG of i.o is
exceeded for mammals foraging on grasses, broadleaf forage, small insects, fruit, and
large insects (RQs range up to 20 at maximum predicted residues). In addition to
35
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potential direct effects, there may be potential for indirect effects to listed species that
are dependent upon a taxa that may experience effects from the use of this pesticide.
The Agency can not quantitatively predict potential acute direct effects to
endangered and threatened estuarine/marine fish or aquatic vascular and non-vascular
plants; nor direct chronic effects to endangerd and threatened fresh water fish and
invertebrates, and estuarine/marine fish and invertebrates and therefore the potential
for effects can not be precluded based on EPA's screening level ecological risk
assessment. In the case of the current lack of effects thresholds for listed aquatic plants,
the potential for indirect effects on listed species with obligate relationships on a given
species of aquatic plant cannot be discounted because definitive RQs for comparison to
the listed species LOCs are unavailable. Potential risks to endangered species identified
in the Environmental Fate and Ecological Risk Assessment and reflected in this RED
for MCPB are based solely on EPA's screening level ecological risk assessment and do
not constitute "may effect" findings under the Endangered Species Act.
6. Risk Characterization
The risk assessment for MCPB is a conservative, screening-level assessment conducted
with the maximum application rate of 1.5 Ib ae/A.
Freshwater and estuarine/marine fish and aquatic invertebrates do not appear to be at
acute risk from exposure to MCPB, and there are no risk concerns for non-endangered aquatic
plants for the pea scenarios that were modeled.
EPA's level of concern is exceeded for chronic risk to mammals that consume grasses,
broadleaf plants, and small insects, although the exceedances are relatively small (RQs range from
1.23 to 6.44; chronic LOG is exceeded if RQ > 1.0). This screening-level assessment assumes
that 100 percent of the diet is comprised of single food types foraged only from treated fields.
The assumption of 100 percent diet from a single food type may not be realistic for chronic
exposures from the single annual application of MCPB to peas because diets are likely to be more
variable over longer periods of time depending on size and forage range of animals.
EPA's level of concern is also exceeded for acute risk to small birds that consume short
grasses, although the exceedances are relatively small (RQs range from 0.34 to 0.80). The
screening-level assessment assumes that 100 percent of the diet is comprised of single food types.
This assumption may be more realistic for acute risks than chronic risks. MCPB is categorized as
moderately toxic to avian species on an acute oral basis, but it is practically non-toxic to avian
species on an acute dietary basis. Based on these acute toxicity data, there is a large differential in
the acute lethality when MCPB is administered as a single gavage for acute oral studies, as
compared to when MCPB is mixed in the feed for acute dietary studies. There are limitations to
both the dose-based and dietary-based method of calculating risk quotients; however, for many
compounds a gavage dose represents a very short-term, high-intensity exposure, whereas dietary
exposure may be of a more prolonged nature. The disparity in mortality between the two types of
36
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studies suggests that the dietary matrix may have a lowering effect for the toxicity of MCPB.
EPA's level of concern is exceeded for terrestrial plants, which is expected based on
MCPB's herbicidal properties. Risks are expected if exposure occurs, but there is very limited
use of MCPB. It is only registered for use on pea crops, and it is approved for use only once per
year, at a maximum rate of 1.5 Ib ae/acre. Total annual use is less than 15,000 pounds.
IV. Risk Management, Reregistration, and Tolerance Reassessment Decision
A. Determination of Reregistration Eligibility
Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of
relevant data concerning an active ingredient, whether products containing the active ingredient
are eligible for reregistration. The Agency has previously identified and required the submission
of the generic (i.e., active ingredient-specific) data to support reregistration of products
containing MCPB as an active ingredient.
The Agency has completed its review of submitted data and its assessment of the human
and ecological risks associated with the use of pesticide products containing the active ingredient
MCPB. Based on a review of these data, the Agency has sufficient information on the human
health and ecological effects of MCPB to make decisions as part of the tolerance reassessment
process under FFDCA and the reregistration process under FIFRA, as amended by FQPA. The
Agency has determined that MCPB-containing products are eligible for reregistration provided
that: (i) required product-specific data are submitted; (ii) the risk mitigation measures outlined in
this document are adopted; and (iii) label amendments are made to reflect these measures. Label
changes are described in Section V. Appendix A summarizes the uses of MCPB that are eligible
for reregistration. Appendix B identifies the generic data that the Agency reviewed as part of its
determination for reregistration eligibility of MCPB, and lists the submitted studies that the
Agency found acceptable.
Based on its evaluation of MCPB, the Agency has determined that MCPB products,
unless labeled and used as specified in this document, would present risks inconsistent with
FIFRA and FFDCA. Accordingly, should a registrant fail to implement any of the risk mitigation
measures identified in this document, the Agency may take regulatory action to address the risk
concerns from the use of MCPB. If all changes outlined in this document are incorporated into
the product labels, then all current risks for MCPB will be adequately mitigated for the purposes
of this determination under FIFRA. Once the Endangered Species assessment is completed,
further changes to these registrations may be necessary as explained in Section IV.D.3.
B. Public Comments and Responses
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Through the Agency's public participation process, EPA worked extensively with
stakeholders and the public to reach the regulatory decisions for MCPB. During the public
comment period on the risk assessments, which closed on January 3, 2006, the Agency received
comments from one private citizen, and the MCPB Task Force. These comments in their entirety
are available in the public docket (EPA-HQ-OPP-2005-0263) at http://www.regulations.gov. A
detailed Response to Comments document is available in the public docket as well.
The RED and technical supporting documents for MCPB are available to the public
through EPA's electronic public docket and comment system, EPA Dockets, under docket
identification (ID) number EPA-HQ-OPP-2005-0263. The public may access EPA Dockets at
http://www.regulations.gov/fdmspublic-relll/component/main. In addition, the MCPB RED may
be downloaded or viewed through the Agency's website at
http ://www. epa. gov/pesticides/reregistration/status.htm.
C. Regulatory Position
1. Food Quality Protection Act Findings
a. "Risk Cup " Determination
As part of the FQPA tolerance reassessment process, EPA assessed the risks associated
with MCPB. An aggregate assessment was conducted for exposures through food and drinking
water. (Residential exposures were not aggregated because MCPB is not registered for
residential use.) EPA has determined that risk from dietary (food and water sources) exposure to
MCPB is within its own "risk cup." The Agency has determined that the human health risks from
these combined exposures are within acceptable levels. In other words, EPA has concluded that
the tolerances for MCPB meet FQPA safety standards. In reaching this determination, EPA has
considered the available information on the special sensitivity of infants and children, as well as
aggregate exposure from food and water.
b. Determination of Safety to the U.S. Population
The Agency has determined that the established tolerances for MCPB meet the safety
standards under the FQPA amendments to Section 408(b)(2)(D) of the FFDCA, and that there is
a reasonable certainty no harm will result to the general population or any other population from
the use of MCPB. In reaching this conclusion, the Agency has considered all available
information on the toxicity, use practices and exposure scenarios, and the environmental behavior
of MCPB. As discussed in Chapter 3, the total acute and chronic dietary (food plus water) risks
are below the Agency's level of concern (< 100% of the PAD) for the general population and all
subgroups. The highest exposed population subgroup was infants (<1 years old) at < 4% of the
aPAD and 10% of the cPAD.
c. Determination of Safety to Infants and children
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The Agency has determined that the established tolerances for MCPB meet the safety
standards under the FQPA amendments to Section 408(b)(2)(C) of the FFDCA, and that there is
a reasonable certainty that no harm will result to infants and children. The safety determination
for infants and children considers the toxicity, use practices, and environmental behavior noted
above for the general population, but also takes into account the possibility of increased dietary
exposure due to the specific consumption patterns of infants and children, as well as the possibility
of increased susceptibility to the toxic effects of MCPB residues in this population subgroup.
In determining whether infants and children are particularly susceptible to toxic effects
from MCPB residues, the Agency considered the completeness of the database for developmental
and reproductive effects, the nature of the effects observed, and other information. The FQPA
safety factor for MCPB has been retained for acute exposures and partially retained for chronic
exposures due to uncertainty in the toxicology database (lack of a DNT study). However, the
toxicity database for MCPB, which is bridged from MCPA, includes acceptable developmental
and reproductive toxicity studies and there is no evidence in the developmental or reproductive
toxicity studies of sensitivity or susceptibility to newborns.
As discussed in Chapter 3, the total acute and chronic dietary (food plus water) risks are
below the Agency's level of concern (< 100% of the PAD) for the general population and all
subgroups. The highest exposed population subgroup was infants (<1 years old) at < 4% of the
aPAD and 10% of the cPAD.
d. Endocrine Disruptor Effects
EPA is required under the FFDCA, as amended by FQPA, to develop a screening program
to determine whether certain substances (including all pesticide active and other ingredients) "may
have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or
other endocrine effects as the Administrator may designate." Following recommendations of its
Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), EPA determined
that there was a scientific basis for including, as part of the program, the androgen and thyroid
hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's
recommendation that EPA include evaluations of potential effects in wildlife. For pesticides, EPA
will use FIFRA and, to the extent that effects in wildlife may help determine whether a substance
may have an effect in humans, FFDCA authority to require the wildlife evaluations. Furthermore,
as the science develops and resources allow, screening of additional hormone systems may be
added to the Endocrine Disruptor Screening Program (EDSP) and MCPB may be subject to
additional screening.
e. Cumulative Risks
Risks summarized in this document are those that result only from the use of
MCPB. The Food Quality Protection Act (FQPA) requires that the Agency consider
available information concerning the cumulative effects of a particular pesticide's
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residues and "other substances that have a common mechanism of toxicity." The
reason for consideration of other substances is due to the possibility that low-level
exposures to multiple chemical substances that cause a common toxic effect by a
common toxic mechanism could lead to the same adverse health effect as would a
higher level of exposure to any of the substances individually. Unlike other pesticides
for which EPA has followed a cumulative risk approach based on a common mechanism
of toxicity, EPA has not made a common mechanism of toxicity finding for MCPB. For
information regarding EPA's efforts to determine which chemicals have a common
mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the
policy statements released by EPA's Office of Pesticide Programs concerning common
mechanism determinations and procedures for cumulating effects from substances
found to have a common mechanism on EPA's website at
http://www.epa.gov/pesticides/cumulative/.
2. Tolerance Reassessment Summary
a. Tolerances Currently Listed Under 40 CFR § 180.318
Tolerances are currently established under 40 CFR §180.318 for residues of MCPB [4-(2-
methyl-4-chlorophenoxy)butyric acid)] per se in/on peas at 0.1 ppm. The Agency has concluded
that the residue of concern for both tolerance enforcement and for dietary risk analysis consists of
MCPB and MCPA, free and conjugated. The tolerance expression will be revised accordingly,
once all data have been submitted (see Table 20). EPA notes that although additional data are
required, there are no dietary risks associated with the tolerance for peas and EPA considers it
reassessed at the current level.
No maximum residue limits (MRLs) for MCPB have been established by Codex for any
agricultural commodity. Additionally, no Canadian or Mexican MRLs have been established for
MCPB.
Table 20. Tolerance Reassessment Summary for Registered MCPB Uses
Commodity
Current
Tolerance
(ppm)
Range of
Residues (ppm)
Tolerance
Reassessment
(ppm)
Comment
Tolerances Listed Under 40 CFR §180.318
Pea
0.1 (N)*
<0.05
0.1
Residue studies must be submitted
depicting the magnitude of both MCPB
and MCPA residues in/on peas.
* The "(N)" designation indicates negligible residues and EPA will propose to remove the "(N)" designation
from all entries to conform to current Agency administrative practice.
D. Regulatory Rationale
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The Agency has determined that MCPB is eligible for reregistration provided that risk
mitigation measures outlined in this document are adopted, and label amendments are made to
reflect these measures.
The following is a summary of the rationale for managing risks associated with the use of
MCPB. Where labeling revisions are warranted, specific language is set forth in the summary
tables of Section V of this document.
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1. Human Health Risk Mitigation
a. Dietary (Food) Risk Mitigation
The Agency's unrefined Tier 1 (100% crop treated) acute and chronic dietary (food only)
risk assessments for MCPB indicated that acute and chronic risk estimates are below the
Agency's level of concern. Therefore, no dietary risk reduction measures are required.
b. Drinking Water Risk Mitigation
Estimated environmental concentrations (EECs) of MCPB and its degradates for both
ground water and surface water sources of drinking water are below the Agency's level of
concern. Therefore, no mitigation is needed for drinking water.
c. Aggregate Risk Mitigation
EPA must consider and aggregate (add) pesticide exposures and risks from three major
sources: food, drinking water, and residential. MCPB has no residential uses. Therefore, the
aggregate exposure risk assessments for MCPB only incorporate exposures and risks from food
and drinking water.
(1) Acute Aggregate Risk
The Agency's acute dietary (food plus water) risk assessment indicated that acute dietary
risks are below the Agency's level of concern. Therefore, no mitigation is required.
(2) Chronic Aggregate Risk
The Agency's chronic dietary (food plus water) risk assessment indicated that chronic
dietary risks are below the Agency's level of concern. Therefore, no mitigation is required.
d. Occupational Risk Mitigation
(1) Handler Exposure
EPA completes handler exposure assessments by using a baseline (long-sleeved shirt and
long pants) exposure scenario and, if required, increasing levels of mitigation such as Personal
Protective Equipment (PPE) or engineering controls to achieve an adequate margin of exposure
(MOE). For MCPB, short- and intermediate-term inhalation risks to occupational handlers are
below the Agency's level of concern (i.e., MOE >100) at baseline (i.e., no respirator) for mixers,
loaders, and applicators. For dermal risks associated with mixing and loading for groundboom
and aerial application, MOEs are above the Agency's level of concern (i.e., MOE < 100) at
baseline, but are below EPA's level of concern (i.e., MOE >100) when chemical-resistant gloves
42
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are added. To mitigate the potential dermal risks to mixers and loaders, chemical-resistant gloves
will be required.
(2) Post-Application Risk Mitigation
EPA assessed short/intermediate-term post-application risks to workers who enter pea
fields recently treated with MCPB to conduct tasks such as scouting and irrigation. EPA did not
assess long-term post-application exposure risks because MCPB is used only once per season.
Using the maximum application rate of 1.5 Ib ae/A and the default dislodgeable foliar residue
value of 20 percent, post-application risks are below the Agency's level of concern (i.e., MOEs
>100) on day zero, or 12 hours after application. EPA has determined that a 12-hour restricted
entry interval is appropriate for MCPB.
2. Environmental Risk Mitigation
EPA's levels of concern are exceeded for acute risk to small-sized birds and terrestrial
plants, and chronic risk to mammals. EPA has determined that the risk mitigation that is
appropriate for environmental concerns at this time is to require medium or coarser droplet sizes
to minimize the potential for spray drift.
3. Endangered Species Considerations
From the screening-level assessment, RQs exceeded the LOCs for endangered
species for some of the exposure scenarios. Chronic RQs exceed the LOCs for
endangered mammals (RQs range from 2 to 20 at maximum residue levels), acute RQs
exceed LOCs for endangered birds (RQs range from 0.2 to 2.26 at maximum residue
levels), and acute RQs exceed the endangered terrestrial plant LOCs for monocots and
dicots (RQs range from 9 to 77).
The Agency has developed the Endangered Species Protection Program to
identify pesticides whose use may cause adverse impacts on endangered and threatened
species, and to implement mitigation measures that address these impacts. The
Endangered Species Act (ESA) requires federal agencies to ensure that their actions are
not likely to jeopardize listed species or adversely modify designated critical habitat. To
analyze the potential of registered pesticide uses that may affect any particular species,
EPA uses basic toxicity and exposure data developed for the REDs and considers it in
relation to individual species and their locations by evaluating important ecological
parameters, pesticide use information, geographic relationship between specific
pesticide uses and species locations, and biological requirements and behavioral aspects
of the particular species, as part of a refined species-specific analysis. When conducted,
this species-specific analysis will take into consideration any regulatory changes
recommended in this RED that are being implemented at that time.
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Following this future species-specific analysis, a determination that there is a
likelihood of potential impact to a listed species or its critical habitat may result in
limitations on the use of MCPB, other measures to mitigate any potential impact, or
consultations with the Fish and Wildlife Service or the National Marine Fisheries
Service, as necessary. If the Agency determines use of MCPB "may affect" listed species
or their designated critical habitat, EPA will employ the provisions in the Services
regulations (50 CFR Part 402). Until that species-specific analysis is completed, the
risk mitigation measures being implemented through this RED will reduce the
likelihood that endangered and threatened species may be exposed to MCPB at levels of
concern. EPA is not requiring specific MCPB label language at the present time relative
to threatened and endangered species. If, in the future, specific measures are necessary
for the protection of listed species, the Agency will implement them through the
Endangered Species Protection Program.
4. Spray Drift Management
The Agency has been working with the Spray Drift Task Force, EPA Regional Offices,
State Lead Agencies for pesticide regulation, and other parties to develop the best spray drift
management practices. The Agency has completed its evaluation of the new database submitted
by the Spray Drift Task Force, a membership of U.S. pesticide registrants, and is developing a
policy on how to appropriately apply the data and the AgDRIFT computer model to its risk
assessments for pesticides applied by air, orchard airblast, and ground hydraulic methods. After
the policy is in place, the Agency may impose further refinements in spray drift management
practices to reduce off-target drift and risks associated with aerial as well as other application
methods where appropriate.
Spray drift is a potential source of MCPB non-target exposure near spraying operations.
This is particularly the case with aerial application, but spray drift exposure may also result from
ground application of MCPB. To minimize the potential for spray drift, the Agency is requiring
medium or coarser droplet sizes for all MCPB end-use products. Additionally, the Agency
encourages the inclusion of best management practices on labels to reduce spray drift. In the
future, MCPB labels may need to be revised to include additional or different drift label
statements.
V. What Registrants Need to Do
The Agency has determined that MCPB is eligible for reregistration provided that
product-specific data are submitted and the mitigation measures stated in this document are
included in upcoming label submissions. In the near future, the Agency intends to issue Data Call-
in (DCI) notices requiring product-specific data and generic confirmatory data. Generally,
registrants will have 90 days from receipt of a DCI to complete and submit response forms or
request time extensions and/or waivers with a full written justification. For product-specific data,
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the registrant will have eight months to submit data and amended labels. For generic data, due
dates can vary depending on the specific studies being required. Listed below are the additional
generic data that the Agency intends to require.
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F. Manufacturing Use Products
1. Additional Generic Data Requirements
The generic database supporting the reregistration of MCPB for the above eligible use has
been reviewed and determined to be substantially complete based on bridging from MCPA data.
However, the data listed below, in Tables 21 and 22, are necessary to confirm the reregistration
eligibility decision documented in this RED.
Table 21. Toxicology and Residue Chemistry Data Requirements
Study Required
Confined Accumulation in Rotational Crops
Study
Magnitude of Residues in Plants
Enforcement Analytical Methods
Developmental neurotoxicity study in rats
[Reserved]
28-day Inhalation Study (abbreviated 90-day
protocol) [Reserved]
Guideline Number
860.1850
860.1300
860.1340
870.6300
870.3465
Comment
Must be conducted with MCPB
Must be conducted with MCPB and
MCPA
Must be conducted with MCPB and
MCPA
Reserved pending outcome of
developmental neurotoxicity study in rats
with MCPA 2-EHE
Reserved pending outcome of 28-day
Inhalation Study with MCPA
Table 22. Environmental Fate and Ecological Toxicity Data Requirements
Study Required
Terrestrial Field Dissipation
Estuarine/marine invertebrate acute EC50
(eastern oyster)
Estuarine/marine fish acute LC50
(sheepshead minnow)
Freshwater fish early life stage
(fathead minnow)
Freshwater invertebrate life cycle (daphnia)
[Reserved]
Estuarine/marine life cycle (mysid) [Reserved]
Estuarine/marine life cycle (fish) [Reserved]
Guideline Number
835.1600
850.1025
850.1075
850.1400
850.1300
850.1350
850.1400
Comment
Reserved pending the outcome of acute
estuarine/marine fish and invertebrate studies.
Reserved pending the outcome of acute
estuarine/marine fish and invertebrate studies.
Reserved pending the outcome of acute
estuarine/marine fish and invertebrate studies.
Reserved pending the outcome of acute
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Study Required
Freshwater fish full life cycle [Reserved]
Guideline Number
850.1500
Comment
estuarine/marine fish and invertebrate studies.
2. Labeling for Manufacturing-Use Products
To ensure compliance with FIFRA, manufacturing use product (MUP) labeling should be
revised to comply with all current EPA regulations, PR Notices, and applicable policies. The
MUP labeling should bear the labeling contained in Table 23 at the end of this section.
B. End-Use Products
i. Additional Product-Specific Data Requirements
Section 4(g) (2) (B) of FIFRA calls for the Agency to obtain any needed product-
specific data regarding the pesticide after a determination of eligibility has been made.
The registrant must review previous data submissions to ensure they meet current EPA
acceptance criteria and if not, commit to conduct new studies. If a registrant believes
that previously submitted data meet current testing standards, then the study MRID
numbers should be cited according to the instructions in the Requirement Status and
Registrations Response Form provided for each product. The Agency intends to issue a
separate product-specific Data Call-In outlining specific data requirements.
2. Labeling for End-Use Products
Labeling changes are necessary to implement measures outlined in Section IV
above. The specific changes and language required are presented in Table 23 below.
Existing stocks time frames will be established case-by-case, depending on the
number of products involved, the number of label changes, and other factors. Please
refer to "Existing Stocks of Pesticide Products; Statement of Policy," Federal Register,
Volume 56, No. 123, June 26,1991.
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C. Labeling Changes Summary Table
In order to be eligible for reregistration, registrants must amend all product labels to incorporate the risk mitigation measures
outlined in Section IV. The following table describes how language on the labels should be amended.
Table 23: Summary of Labeling Changes for MCPB
Description
Amended Labeling Language
Placement on Label
Manufacturing Use Products
One of these statements may
be added to a label to allow
reformulation of the product
for a specific use or all
additional uses supported by a
formulator or user group
Environmental Hazards
Statements Required by the
RED and Agency Label
Policies
"Only for formulation into an herbicide for use on peas."
"This product may be used to formulate products for specific use(s) not listed on the MUP label if the
formulator, user group, or grower has complied with U.S. EPA submission requirements regarding
support of such use(s)."
"This product may be used to formulate products for any additional use(s) not listed on the MP label if the
formulator, user group, or grower has complied with U.S. EPA submission requirements regarding
support of such use(s)."
"Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or waters
unless in accordance with the requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not
discharge effluent containing this product into sewer systems without previously notifying the sewage
treatment plant authority. For guidance, contact your State Water Board or Regional Office of the
Environmental Protection Agency."
Directions for Use
Directions for Use
Precautionary
Statements
End Use Products Intended for Occupational Use (WPS)
PPE Requirements
Established by the RED1
"Personal Protective Equipment (PPE)
Immediately
following/below
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for liquid formulations
Some materials that are chemical-resistant to this product are (registrant inserts correct chemical-
resistant material). If you want more options, follow the instructions for category [registrant inserts A,
B, C, D, E, F, G, or H] on an EPA chemical-resistance category selection chart.
Mixers, loaders, and other handlers must wear:
Long-sleeved shirt
Long pants
Shoes plus socks
Chemical-resistant gloves when mixing, loading or exposed to the concentrate. "
Precautionary
Statements: Hazards to
Humans and Domestic
Animals
User Safety Requirements
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables
exist, use detergent and hot water. Keep and wash PPE separately from other laundry."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals immediately
following the PPE
requirements
Engineering Controls
"Engineering Controls:
Pilots must use an enclosed cockpit that meets the requirements listed in the Worker Protection Standard
(WPS) for agricultural pesticides [40 CFR 170.240 (d)(6)]."
Precautionary
Statements: Hazards to
Humans and Domestic
Animals (Immediately
following PPE and User
Safety Requirements.)
User Safety
Recommendations
"User Safely Recommendations
Users should wash with plenty of soap and water before eating, drinking, chewing gum, using tobacco, or
using the toilet.
Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put
on clean clothing.
Users should remove PPE immediately after handling this product. Wash the outside of gloves before
removing. As soon as possible, wash thoroughly and change into clean clothing."
Precautionary
Statements under:
Hazards to Humans and
Domestic Animals
immediately following
Engineering Controls
(Must be placed in a
box.)
Environmental Hazards
"Environmental Hazards
Precautionary
Statements immediately
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Avoid spray drift as this product may injure susceptible crops and plants such as cotton, beans, grapes,
tomatoes and ornamentals. (Course sprays are less likely to drift.) Do not use same spray equipment for
other purposes unless thoroughly cleaned prior to use. Do not apply this product through any type of
irrigation system."
following the User
Safety
Recommendations
Restricted-Entry Interval
"Do not enter or allow worker entry into treated areas during the restricted-entry interval (REI) of 12
hours."
Early Re-entry Personal
Protective Equipment
established by the RED.
"PPE required for early entry to treated areas that is permitted under the Worker Protection Standard and
that involves contact with anything that has been treated, such as plants, soil, or water, is:
Coveralls,
Shoes plus socks,
Chemical-resistant gloves made of any waterproof material"
Directions for Use,
Agricultural Use
Requirements Box
General Application
Restrictions
"It is a violation of Federal Law to use this product in a manner inconsistent with its labeling. Read entire
label before using this product."
"Do not apply this product in a way that will contact workers or other persons, either directly or through
drift. Only protected handlers may be in the area during application. For any requirement specific to your
State or Tribe, consult the agency responsible for pesticide regulations."
Place in the Direction
for Use directly above
the Agricultural Use
Box.
Spray Drift Label Language
for Products Applied as a
Spray
"Apply only as a medium or coarser spray (ASAE standard 572) or a volume mean diameter of 300
microns or greater for spinning atomizer nozzles."
"A variety of factors including weather conditions (e.g., wind direction, wind speed, temperature, relative
humidity) and method of application (e.g., ground, aerial, airblast, chemigation) can influence pesticide
drift. The applicator and grower must evaluate all factors and make appropriate adjustments when
applying this product.
WIND SPEED:
Do not apply at wind speeds greater than 10 mph at the application site."
DROPLET SIZE:
"Apply as a medium or coarser spray (ASAE standard 572)."
RELEASE HEIGHT (GROUND APPLICATION):
Directions for Use
under General
Precaution and
Restrictions
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"Apply using a nozzle height of no more than 4 feet above the ground or crop canopy."
RELEASE HEIGHT (AERIAL APPLICATION):
"Do not release spray at a height greater than 10 feet above the ground or crop canopy."
1 PPE that is established on the basis of Acute Toxicity of the end-use product must be compared to the active ingredient PPE in this document. The more protective PPE
must be placed in the product labeling. For guidance on which PPE is considered more protective, see PR Notice 93-7.
Instructions in the Labeling section appearing in quotations represent the exact language that should appear on the label.
Instructions in the Labeling section not in quotes represents actions that the registrant should take to amend their labels or product
registrations.
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VI. Related Documents and How to Access Them
This interim Reregistration Eligibility Document is supported by documents that are presently
maintained in the OPP docket under docket number EPA-HQ-2005-0263. The OPP docket is
located in Room 119, Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA. It is open
Monday through Friday, excluding legal holidays from 8:30 am to 4 pm. The documents are also
available on-line in the Federal Docket Management System (FDMS) at http://www.regulations.gov.
The docket initially contained preliminary risk assessments and related documents as of
November 2, 2005. Sixty days later, on January 3, 2006, the public comment period closed. The
EPA then considered the comments received, revised the risk assessments as necessary. EPA then
added formal "Response to Comments" documents, the Reregistration Eligibility Decision (RED)
document, and the revised risk assessments to the docket on July 21, 2006.
All documents, in hard copy form, may be viewed in the OPP docket room or downloaded or
viewed via the Internet at http://www.regulations.gov.
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Appendix A:
Use Patterns Eligible for Reregistration for use on Peas
Table 1. MCPB use on Peas
Application Type,
Equipment
Spray/ground and
Aerial
Formulation
Thistrol Herbicide
(7 1368-5) and
Sodium MCPB
Solution (7 1368-7)
Max. Single
App. Rate
(Ibs ae/A)
1.5
Seasonal Max.
(Ibs ae/A/Yr)
1.5
PHH
(Days)
1
REI
(Hours)
24
Restrictions/Comments
Use single layer PPE
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Appendix B:
Data Supporting Guideline Requirements of the Reregistration of MCPB
Table 1. Product Chemistry
New Guideline
Number
860.1400
Old Guideline
Number
171-4H
Requirement
Magnitude of Residue in Irrigated Crops
Use
Peas
Citation(s)
44754101
Table 2. Ecological Effects
New Guideline
Number
850.2100
850.2200
850.2200
850.1075
850.1075
850.1010
850.1100
870.3100
870.3150
870.3700
870.3700
870.3800
850.4150
850.5400
850.5400
Old Guideline
Number
71-1
7 1-2 A
71-2B
72- 1C
72-1A
72-2A
82-1
82-1A
82- IB
83-3A
83-3B
83-4A (MCPA)
122-1B
122-2A
122-2B
Requirement
Bobwhite Quail
Avian Acute Dietary Toxicity Test, Bobwhite quail
Avian Acute Dietary Toxicity Test, Mallard
Fish Acute Toxicity Test Rainbow Trout
Fish Acute Toxicity Test, Bluegill Sunfish
Invertebrate Acute Toxicity Test, Freshwater
Daphnids
Acute Oral Toxicity Test, Rat
Subchronic Oral Toxicity Test, (90-day Feeding,
rodent)
Subchronic Oral Toxicity Test, (90day - Feeding,
non-rodent)
Prenatal Developmental Toxicity (Teratogenicity),
RAP
Prenatal Developmental Toxicity (Teratogenicity),
Rabbit
2-generation Reprodution and Fertility
Terrestrail Plant, Tier 1 (Vegetative Vigor)
Algal Toxicity, Tier 1
Algal Toxicity, Tier 2
Use
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Citation(s)
42560801
42560802
42560803
42532608
42532601
42532602
144801,116340
42883602,42883601
116345,116344,
42883603
40865402
40865401
40041701
42560804, 43083205
(MCPA)
42532605,42532603,4
2532609, 42532606
42532605,42532609,
42532603, 42532606
54
-------
850.4225
850.4250
850.4400
850.3020
123-1A
123-1B
123-2
141-1
Seedling Germination and Seedling Emergence,
Tier 2
Vegetative Vigor, Tier 2
Aquatic Plant Toxicity Test Using Duckweed
Lemma
Honey Bee Acute Contact Toxicity
Peas
Peas
Peas
Peas
42560804
42560804
42532604
42532607
Table 3. Toxicology
New Guideline
Number
870.1100
870.1200
870.1300
870.2400
870.2500
870.2600
870.3100
870.3150
870.3200
870.3700a
870.3700b
870.5100
870.5375
870.5550
870.7485
Old Guideline
Number
81-1
81-2
81-3
81-4
81-5
81-6
82-1A
81-1B
82-3
83-3A
83-3B
84-2
84-2B
84-2
85-1
Requirement
Acute Oral Toxicity-Rat
Acute Dermal Toxicity-Rabbit/Rat
Acute Inhalation Toxicity-Rat
Primary Eye Irritation- Rabbit
Primary Skin Irritation - Rabbit
Dermal Sensitization, Guinea Pig
Subchronic Oral Toxicity Test (90 Day Feeding -
Rodent)
Subchronic Oral Toxicity Test (90 Day Feeding -
Non-Rodent)
Repeated Dose Dermal Toxicity Test (21 Day),
Rabbit
Prenatal Developmental Toxicity, (Teratogenicity),
Rat
Prenatal Developmental Toxicity, (Teratogenicity),
Rabbit
Bacterial (Escherichia Coll Wp2 and Wp2 uvrA)
Reverse Gene Mutation Assay Test
In Vitro Mammalian Cytogenetics Tests (Structural
Chromosomal Aberration Test)
Unscheduled DNA synthesis in Mammalian Cells
in Culture
Metabolism and Pharmacokinetics (General
Metabolism)
Use
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Peas
Citation(s)
116340,144801
116342,144799
41630001
116343,144797
144798
144800
42883602
42883603
116346
40865402
40865401
40564302, 40564303
40564301
40564304
44818101
55
-------
Table 4. Environmental Fate
New Guideline
Number
835.2120
835.2240
835.2410
835.4100
835.4200
835.1230
Old Guideline
Number
161-1
161-2
161-3
162-1
162-2
163-1
Requirement
Hydrolysis of Parent and Degradates as a Function
of pH at 25°C (Hydrolysis)
Direct Photolysis Rate of Parent and Degradates in
Water (Photodegradation in water)
Photodegradation of Parent and Degradates in Soil
(Photodegradation in soil)
Aerobic Soil Metabolism Study
Anaerobic Soil Metabolism Study
Sediment (Leaching) and Soil
Absorption/desorption for Parent and Degradates
Use
Peas
Peas
Peas
Peas
Peas
Peas
Citation(s)
42574301
42574302
43829901
43247601
43015501
42693701,43466401
56
-------
Appendix C:
Technical Support Documents
Additional documentation in support of this RED is maintained in the OPP docket, located in
2777 Crystal Drive (One Potomac Yard) Arlington, VA 22202. It is open Monday through Friday,
excluding legal holidays, from 8:30 AM to 4:30 PM.
The docket initially contained preliminary human health and ecological effects risk
assessments and related documents that were published November 2, 2005. The public comment
period closed sixty days later, on January 3, 2006. The EPA then considered the comments received
and revised the risk assessments where appropriate. Revised ecological risk assessments, as well as
additional supporting documents will be published in the docket with this RED.
57
-------
Appendix D:
Citation Considered to be Part of the Database Supporting the Reregistration
Eligibility Decision (Bibliography)
Open Literature
Books
Howard, P.H. and W.M. Meylan. 1997 Handbook of Physical Properties of Organic Chemicals.
Lewis Publishers, New York. Page 121.
Podall, H. 2002. CBI Product Chemistry Review, March 8, 2002
Tomlin, C.D.S., ed. 1997. The Pesticide Manual #65 MCPB Sodium Salt, British Corp Protection
Council, 11th ed, Farnham, Surrey, UK. Page 254.
WSSA (Weed Science Society of America). 1994. Herbicide Mode of Action and Sugarbeet Injury
Symptoms. North Dakota State University of Agriculture and Applied Science Fargo, ND.
Ferrell, J.A., G.E. Mac Donald, B.J. Brecke, A.C. Bennett, and J. Tredaway Ducar. 2005. Florida's
Organo-Auxin Herbicide Rule-2005. University of Florida, Institute of Food and Agricultural
Sciences, Gainesville, FL.
Heimann, M.F. and R.C. Newman. 1997. Plant injury due to turfgrass broadleaf weed herbicides.
University of Wisconsin - Cooperative Extension, Madison, WI.
Lingenfelter, D.D. and N. L. Hartwig. 2003. Introduction to Weeds and Herbicides. Penn State
College of Agricultural Sciences - Agricultural Research and Cooperative Extension Page 1-20.
Bibliography
PC Code: 019201
116340
116342
Holsing. G.11Q6Q) Acute Oral—Rats; MCPB Technical: Project No. 517-102.
Final rept. (Unpublished study received on un- Known date under iFiosi;
prepared by TRW, Inc., submitted by Rhodia, Inc., New Brunswick, NJ;
CDL:09i885-B)
Holsing, G. (1.969) Acute Dermal ^-Rabbits: MCPB Technical: Project No..
517-103. Final rept. UJnpubTisned stuoy receivedon un- known date under
58
-------
prepared by TRW, Inc., submitted by Rhodia, Inc., New Brunswick,
NJ; CDL:09i885-D)
116343
Holsing, G. (196,0) Draize Eye—Rabbits: MCPB Technical: Project No. 517-
105. Fmarrept. (Unpublished stud received on un- Known date under
; prepared by TRW, Inc., submitted by Rhodia, Inc., New Brunswick,
NJ; CDL:09i885-E)
116345
HoMm* G.J Ferrell, J. (i97_oli3-week Dieta^Administration— Dogs:
MCPBrProject No. 517-167. Final rept. (Unpublisned study received on
unknown date under iFiosi; prepared by TRW, Inc., submitted by Rhodia,
Inc., New Brunswick, NJ; CDL: 091885-6)
116346
Weath.erhokz.VV• Voelker, R. (1970) Threje-weekJlepeated Dermal--
Rabbits: MCFB: Project N6. 517-104. FinaTrept. (Unpublished study
received on unknown date under iFiosi; prepared by TRW, Inc., submitted
by Rhodia, Inc., New Brunswick, NJ; CDL: 091885-!!)
144797
Li
T
ett, M.: Parc
nical Acid:
ll, B. fmSsUrritanrEffects on thellabhit Ee of
4li9&D/AHM 197 SET UhpublisTieJ stud
Huntingdon Research Centre pic. 7 p.
y prepared by
144798 Liggett, M.: Parcell, B./lof
Technical Acid: 84li2&Dy^
Huntingdon Research Centre pic. 6 p.
npublisne
I bit Skin of MCP.
study pre- pare
by
144799
£ynoch,,S.fiQ85), Acute Dermal Tqxicity to Rats of MCEB Technical Acid:
S515OT5/AHM lo/AC. UnpuDlished study prepared oy Hunting- don
Research Centre pic. 7 p.
144800
SeaberJ. (1985) Delayed Contact Hypersensi.tivity, in the-Guinjea- Pi
MCPBTecnnidal Acid': SsiigD/AHM^o/SS. UnpublisTied study pre
by Huntingdon Research Centre pic. 14 p.
with
'ared
144801
£ynoch, 8^1985) Acute OraLToxicity to Rats of MCPR Technical Acid:
S5131D/AHM 157AC. Unpublished study preparedly Hunting- don
Research Centre pic. 12 p.
40564301
SanSebastian, .L(iQ87) 2-Methyl-4-chlorophenoxybutyric Acid (MCPB
Acid):Tn vitro Chromosome Aberration ArfaTysis in Chinese Hamster Ovary
(CHO) Cells: Laboratory Project ID PH 32O-RP-oqi- 87. Unpublished
study prepared by Pharmakon Research Interna- tional, Inc. 34 p.
59
-------
40564302
Stankowski, L. (4987) £-Methyl-4-chlorophenoxybutyric Acid (M(
Acid): Ames/Salmonella Plate Incorporation Assay: Laboratory Pi
ICPB
:o~fpofafionAssayy LabbraTdry Project ID
PH soi-RP-ooi-Sy. Unpublished study prepared by Pharmakon Research
International, Inc. 22 p.
40564303
Stankowski,,LJmSS) ©-Methyl^TcMorophenowbJityric.acid (MCPB
Acid): CHO/HPRTMammalian CelrForw&rdGerYe Mutation Assay:
Laboratory Project ID PH siy-RP-ooi-Sy. Unpublished study pre- pared by
Pharmakon Research International, Inc. 67 p.
40564604
arfknechtTT. (1987) (§)-Methyl^chlor,m}henpxyhutyric Acid (MCPB
.cid): Rat Hepatocyterrimary Culture/DNA Repair Test: Laboratory
Project ID PH 3ii-RP-ooi-87. Unpublished study pre- pared by
Pharmakon Research International, Inc. 68 p.
40865401
TyLJL; Keeper-Bradley, T. (1988) DevelopmentalToxicitv Eyaluati- on of
MCPB Administered by Gavage to New Zealand White Rabbits: Taboratory
Project ID 51-547. Unpublished study prepared by Bu- shy Run Research
Center. 241 p.
40865402
TyLR. (198 SXBeyelopmenial Tpxicily Evaluation of MCPB Administe- red
by Gavage 10 CD (Sprague Dawley) Rats: Laboratory Project ID 51-532.
Unpublished study prepared by Bushy Run Research Cente- r. 299 p.
41630001
Jackson, G^Hardy,,C.j Lewi^D.: eLal. (i9$5) MCPBTTechnical Acid Acute
Inhalation Toxicity Study in Rats 4-Hour Exposure: Lab Project Number:
AHMi7/8si88. Unpublished study prepared by Hungtindon Research
Centre, Ltd. 47 p.
42574301 pas. Y. Q.9Q2)1Hydrolvsis of (carbon 14)MCPB in Aqueous Solutions,.. , ,
BuffereaafpH 5, 7 and 9: Lab Project Number: 92010: 92-06. Unpublished
study prepared by Innovative Scientific Services, Inc. 77 p.
42574302 pac Y. Q.9Q2)TPhotodeJgradationAof Icarboii 14)MCPB irLAquepus Solutions
Bufferea afpH 5, 7 ancrcj under ArtmcialISumight: Lab Project Number:
92011: 92-07. Unpublished study prepared by Innovative Scientific
Services, Inc. 174 p.
42693701 Rpbspn. M.1(i993)11Determination of Adsorption/Desorption Characteristics
of 4-C2-Methyi,4-Cnloropnenoxy) Butyric Acid (MCPB/in Soil: Final
Report: Lab Project Number: 68/127: 7414. Unpublished study prepared by
60
-------
Hazleton UK. 81 p.
42883601
Irutter, J./ ,
Rats:Tinal eport: Lai) roject umber: 650-17
prepared by Hazleton Washington, Inc. 275 p.
icity Stud with MCPJ3 in
npublished study
42883602
Trutter, J. (19,93) ^Week Dietary Tpxicity Study mth^MCPB in Rats: Final
Report: Lab Project Number: HWA 656-174. Unpublished: study prepared
by Hazleton Washington, Inc. 439 p.
42883603
nalgard, D. (19 9 3 Us-Week DietaryTToxicity Study Twith MCPB in Dogs
FmaTReport: Lao Froject Numberr HWA 656-172. Unpublished study
prepared by Hazleton Washington, Inc. 406 p.
43015501
Goodyear. AJ'iqgs) Carbpn 14-MCPB: Anaerobic Soil Metabolism.: JFinal,
Report: Tab Project Number: 58/131-1015: 68/131: 200352. Unpublished
study prepared by Hazleton UK. 90 p.
43247601
John-A.- Jones, M.: Lowden, P.: etal. (1994) MCPB-Aerobic Soil ,
MetaboTism: Lab Project Number:7/93/194. Unpublished study prepared
by Rhone-Poulenc Agriculture Ltd. 108 p.
43466401
P92/333- Unpublished study prepared by Rhone-Poulenc Agriculture Ltd.
142 p.
43829901
is Study:
^^^-^ John, A • LpwdenxP.:et al. (0995) MCPB Soil Photolysi
AmendedReport: Lab Project Number: F92/I2 6 Unpublished study
prepared by Rhone-Poulenc Agriculture Ltd. 75 p. (Amended version of
42519101).
44754101
Corley, J.: Kunke
CRere'gistration):
^^y,«.. xw.11^^. ^,. ^yyy, ^ICPB: Magnitude o£JR.esidue on Pea _ .
teregistfation): Lab Project Number: d547O.94-CAR23: O547O.94-CA52:
O547O.94-NY17. Unpublished study prepared by University of California.
423 P-
44818101 Thornley. K. (logSO (Carbon-i4)-MCP.B: AStudy of Adsorntion, ^ . ^
Distribution, Metabolism, and ExcretionTolIowing Qral Administration to
the Rat: Final Report: Lab Project Number: 785/10-01141. Unpublished
study prepared by Covance. 195 p.
61
-------
PC Code: 019202
MRID
CITATION
42532601
Bettencourt, M. (iQQ2).MCPB Sodium—Acute Joxicity to BluegUl Sunfish.
[Lepomis macrocmrus) under Flow-through Conditions: Finar Report: Lab
Project Number: 92-8-4363:10566.0392.6226.105. Unpublished study
prepared by Springborn Labs, Inc. 64 p.
42532602
Putt. A, (1992) MCPB Sodiurn-Acute To
;naj under Flow-througn Condit
ity^to Daphnids (Daphnia
magnaj uner ow-trougn onitions: nal Report: Lao Project
Number: 92-7-4351:10566. 0392. 6228.115. Unpublished study prepared
by Springborn Labs, Inc. 2 p.
42532603
Hoberg, JT (1992} MCPB Sodium--Toxicity to the Freshwater Blue-green
Alga, Ariabaena nos-aquae: Final Report: "Lab Project Number: 92-8-4381:
10566.0392.6230.420. Unpublished study prepared by Springborn Labs,
Inc. 54 p.
42532604
H
Unpublished study prepared by Springborn Labs, Inc. 61 p.
ober
malJ
£, J. (1992.) MCPB Sndium—Toxicity tp_the Duckweed Lemnagibba:
report: Lab Project JNumber: 92-8-5368:10506. 0392.6229.410.
42532605
Hoberg. J. (1992).MCPB Sodium-^Tpxicity to the Freshwater Green Alga,
Selenastrum capncornutum: Final Report: Lab Project Number: 92-8-
4361:10566.0392.6232.430. Unpublished study prepared by Springborn
Labs, Inc. 58 p.
42532606
Hoberg, J. (1992) MCPB^odium-TpxicityJo the Marine Diatom,
SKeletonema costatumfTinaTReport: Lab Project Number: 92-8-4372:
10566.0392.6233.450. Unpublished study prepared by Springborn Labs,
Inc. 59 p.
42532607
L. v « i j_vvfT-i/H-ix^LALJ-' VM^H^^-A 1 QXlCljy OlJVll^r',
Apis meIImoraL.J: Lab Project Number: CAR 169-92. Unpu
study prepared by California Agricultural Research, Inc. 22 p.
d;um Salt to Honey ,
Liblished
42532608
^ttancourt, M. (199.2) MCPB Scidium-.-Acute Tpxiqity to Rajnbpw Troi.it
Jncorrhynchus mykiss J under Tuow-through Co:
w-through Conditions: Final Report:
62
-------
Lab Project Number: 92-7-4338:10566.0392.6227.108. Unpublished
study prepared by Springborn Labs, Inc. 64 p.
42532609
Hoberg, J. (1992.) MCPB Spdium—Toxicity to the Freshwater Diatom.
Navicma pemculosa: Final Report: LabProject Number: 92-10-4448:
10566.0392.6231.440. Unpublished study prepared by Springborn Labs,
Inc. 60 p.
42560801
ederserv-CL; Helsten B. (4-9020 MCPB Sodium: i4,-da^Acute_OralLD^o,
tudy in Bobwhite Quail: LabTrqject Number: 108-016-03. UnpuDnsned
study prepared by Bio-Life Associates, Ltd. 59 p.
42560802
gederserLC.; Helsten, B. 0-9020 MCPBJSodium: 8-day Acute Dietary LC
tudy in BoDwhite Quail: Lab Project Number: 108-014-01.Unpubnsne
study prepared by Bio-Life Associates, Ltd. 103 p.
42560803
edersen, C • Helsten. B. (1992) MCPB Sodium: 8-day Acute Dietary LCso
tudy in Mallard Ducklings: Lao Project Number: 108-015-02.
Unpublished study prepared by Bio-Life Associates, Ltd. 103 p.
42560804
Christensen. 1C (10,92) MCPB Sodium- Determination of Effects^on Seed
Germination, Seedling Emergence and Vegetative Vigor oTTen Plant
Species: Final Report: Lab Project Number: 92-8-4377. Unpublished study
prepared by Springborn Labs, Inc. 208 p.
44754101
Corley, J.: Kunke
CRere'gistration):
^^y,«.. i-w^^i, ^,. ^yyy, ^ICPB: Magnitude ofJR.esidue on Pea _ .
Lere'gistfation): Lab Project Number: O547O.94-CAR23: O547O.94-CA52:
O547O.94-NY17. Unpublished study prepared by University of California.
423 P-
PC Code: 030501
MRID
CITATION
40041701
43083205
MacKerizie,JC. (1986,) TwQr-Generation Reproductipn -Study with MCPAJn
Rats: Final Report: Study No. 6148-100. UnpubTisnea study pre- pareaby
Hazleton Laboratories America, Inc. 1304 p.
Hoberg,
-------
Species: Final Report: Lab Project Number: 10566.0493. 6280.610: 93-8-
4888. Unpublished study prepared by Springborn Laboratories, Inc. 246 p.
106595
WsSa^giSS
V- etal. (i9$o) Suhchrpnic (i^week)
eagle Dogs: ReporfNo. R 647«rFmal rept.
(Unpublished study received Jul 6,1982 under unknown admin, no.;
prepared by Centraal Instituut Voor Vpedingsonderzoek, TNO, Neth.,
submitted by Diamond Shamrock Agricultural Chemicals, Cleveland, OH;
CDL:247854-A; 247855; 247856)
165471 Kirsch.-P. (1985) Report on the Study of the Toxicity of MCPA in Rats after
3 Months Administration in iheThei: [Range-finding Study for 2-year
Oncogenicity Study in Rats]: Project No. 3180046/8302. Unpublished
study prepared by BASF Ag. 381 p.
42723801 Hellwig J.: HUdebrand. B. (1993) Study,pf the Prenatal T.oxicity of MCPA-
Acid iirRats aftert)ral Administration (Gavage): Lab Project JNumber:
3ORO374/91O96. Unpublished study prepared by BASF Aktiengesellshaft.
302 p.
42723802
ildebrand,
lie
)3) Study.pfJhePr
lillo L.
wi
.cid i:
icl±.LVJ.. -»*, .^ -^ -- --. --
er OraTAdrmmstrationCGavage): La Project o.
4ORO374/91O95. Unpublished study prepared by BASF Aktiengesellshaft.
230 p.
43562601
Mellert, W^ X>eckardt. K.rKaufmann^ W • et al. (i994)M,CPA-Acid~
SuDchrqnic Oral Dietary Toxicity and Neurotoxicrty Study in Wisfar Rats:
Lab Project Number: 50^374/91133. Unpublished study prepared by
BASF Aktiengesellschaft. 723 p.
64
-------
Appendix E:
Generic Data Call-in
The Generic Data Call-In will be posted at a later date. See Chapter V of the MCPB RED for a list
of studies required.
65
-------
Appendix F:
Product Specific Data Call-In
The product specific Data Call-In will be posted at a later date.
66
-------
Appendix G:
EPA's Batching of MCPB Products for Meeting Acute Toxicity Data
Requirements for Reregistration
EPA'S BATCHING OF MCPB PRODUCTS FOR MEETING ACUTE TOXICITY DATA
REQUIREMENTS FOR REREGISTRATION
In an effort to reduce the time, resources and number of animals needed to fulfill
the acute toxicity data requirements for reregistration of products containing MCPB as the
active ingredient, the Agency has batched products which can be considered similar for
purposes of acute toxicity. Factors considered in the sorting process include each
product's active and inert ingredients (identity, percent composition and biological
activity), type of formulation (e.g., emulsifiable concentrate, aerosol, wettable powder,
granular, etc.), and labeling (e.g., signal word, use classification, precautionary labeling,
etc.). Note that the Agency is not describing batched products as "substantially similar"
since some products within a batch may not be considered chemically similar or have
identical use patterns.
Using available information, batching has been accomplished by the process
described in the preceding paragraph. Notwithstanding the batching process, the Agency
reserves the right to require, at any time, acute toxicity data for an individual product
should the need arise.
Registrants of products within a batch may choose to cooperatively generate,
submit or cite a single battery of six acute toxicological studies to represent all the
products within that batch. It is the registrants' option to participate in the process with all
other registrants, only some of the other registrants, or only their own products within a
batch, or to generate all the required acute toxicological studies for each of their own
products. If a registrant chooses to generate the data for a batch, he/she must use one of
the products within the batch as the test material. If a registrant chooses to rely upon
previously submitted acute toxicity data, he/she may do so provided that the data base is
complete and valid by today's standards (see acceptance criteria attached), the formulation
tested is considered by EPA to be similar for acute toxicity, and the formulation has not
been significantly altered since submission and acceptance of the acute toxicity data.
Regardless of whether new data is generated or existing data is referenced, registrants
must clearly identify the test material by EPA Registration Number. If more than one
confidential statement of formula (CSF) exists for a product, the registrant must indicate
the formulation actually tested by identifying the corresponding CSF.
In deciding how to meet the product specific data requirements, registrants must
follow the directions given in the Data Call-In Notice and its attachments appended to the
RED. The DCI Notice contains two response forms which are to be completed and
submitted to the Agency within 90 days of receipt. The first form, "Data Call-In
67
-------
Response," asks whether the registrant will meet the data requirements for each product.
The second form, "Requirements Status and Registrant's Response," lists the product
specific data required for each product, including the standard six acute toxicity tests. A
registrant who wishes to participate in a batch must decide whether he/she will provide
the data or depend on someone else to do so. If a registrant supplies the data to support a
batch of products, he/she must select one of the following options: Developing Data
(Option i), Submitting an Existing Study (Option 4), Upgrading an Existing Study (Option
5) or Citing an Existing Study (Option 6). If a registrant depends on another's data, he/she
must choose among: Cost Sharing (Option 2), Offers to Cost Share (Option 3) or Citing an
Existing Study (Option 6). If a registrant does not want to participate in a batch, the
choices are Options i, 4, 5 or 6. However, a registrant should know that choosing not to
participate in a batch does not preclude other registrants in the batch from citing his/her
studies and offering to cost share (Option 3) those studies.
Five products were found which contain MCPB as the active ingredient. These products
have been placed in one batch and a no batch group in accordance with the active and
inert ingredients and type of formulation..
Batching Instructions:
No Batch: Each product in this Batch should have its own data generated.
NOTE: The technical acute toxicity values included in this document are for informational
purposes only. The data supporting these values may or may not meet the current
acceptance criteria.
Batch i
EPA Reg. No.
15440-28
71368-8
% Active Ingredient
95-5
97
No
Batch
EPA Reg. No.
15440-38
71368-5
% Active Ingredient
23-5
23-5
68
-------
No
Batch
EPA Reg. No.
71368-7
% Active Ingredient
43.85
69
-------
Appendix H:
List of Registrants Sent This Data Call-In
A list of registrants sent this Data Call-In will be posted at a later date
A H MARKS & CO LTD
Richard J. Otten
Official Address:
PMB 239, 7474 Creedmoor Road
Raleigh, North Carolina 27613
United States
Agent Phone: (919) 846-7860
NUFARM. INC.
Theodore D. Head
Official Address
150 Harvester Drive Suite 200
Burr Ridge, Illinois 60527
United States
Agent Phone: (630) 455-2000
70
-------
Appendix I:
List of Available Related Documents and Electronically Available Forms
Pesticide Registration Forms are available at the following EPA internet site:
http ://www. epa. gov/opprdOO 1 /forms/
Pesticide Registration Forms (These forms are in PDF format and require the Acrobat reader)
Instructions
1. Print out and complete the forms. (Note: Form numbers that are bolded can be filled
out on your computer then printed.)
2. The completed form(s) should be submitted in hardcopy in accord with the existing
policy.
3. Mail the forms, along with any additional documents necessary to comply with EPA
regulations covering your request, to the address below for the Document Processing
Desk.
DO NOT fax or e-mail any form containing 'Confidential Business Information' or 'Sensitive
Information.'
If you have any problems accessing these forms, please contact Nicole Williams at (703) 308-5551
or by e-mail at williams.nicole@epa.gov.
The following Agency Pesticide Registration Forms are currently available via the internet:
at the following locations:
8570-1
8570-4
8570-5
8570-1
7
8570-2
Application for Pesticide
Registration/ Amendment
Confidential Statement of
Formula
Notice of Supplemental
Registration of Distribution of a
Registered Pesticide Product
Application for an Experimental
Use Permit
Application for/Notification of
http://www.epa.gov/opprdooi/forms/8Fi7
o-i.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
o-4.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
o-Fi.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
O-17.pdf
httD://www.eDa.gov/ODDrdooi/forms/8Fi7
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5
8570-2
7
8570-2
8
8570-3
o
8570-3
2
8570-3
4
8570-3
5
8570-3
6
8570-3
7
State Registration of a Pesticide
To Meet a Special Local Need
Formulator's Exemption
Statement
Certification of Compliance with
Data Gap Procedures
Pesticide Registration
Maintenance Fee Filing
Certification of Attempt to Enter
into an Agreement with other
Registrants for Development of
Data
Certification with Respect to
Citations of Data (PR Notice
98-5)
Data Matrix (PR Notice 98-5)
Summary of the
Physical/ Chemical Properties (PR
Notice 98-1)
Self-Certification Statement for
the Physical/Chemical Properties
(PR Notice 98-1)
o-2Fi.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
o-27.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
o-28.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
O-3O.pdf
http://www.epa.gov/opprdooi/forms/8Fi7
o-32.pdf
http://www.epa.gov/opppmsdi/PR Notice
s/prqS-Fi.Ddf
http://www.epa.gov/opppmsdi/PR Notice
s/prqS-Fi.pdf
http://www.epa.gov/opppmsdi/PR Notice
s/prqS-i.pdf
http://www.epa.gov/opppmsdi/PR Notice
s/prqS-i.pdf
Pesticide Registration Kit
Dear Registrant:
www. epa. gov/pesticides/registrationkit/
For your convenience, we have assembled an online registration kit which contains the
following pertinent forms and information needed to register a pesticide product with the U.S.
Environmental Protection Agency's Office of Pesticide Programs (OPP):
1. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal
Food, Drug and Cosmetic Act (FFDCA) as Amended by the Food Quality Protection
Act (FQPA) of 1996.
2. Pesticide Registration (PR) Notices
a. 83-3 Label Improvement Program—Storage and Disposal Statements
b. 84-1 Clarification of Label Improvement Program
c. 86-5 Standard Format for Data Submitted under FIFRA
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d. 87-1 Label Improvement Program for Pesticides Applied through Irrigation
Systems (Chemigation)
e. 87-6 Inert Ingredients in Pesticide Products Policy Statement
f. 90-1 Inert Ingredients in Pesticide Products; Revised Policy Statement
g. 95-2 Notifications, Non-notifications, and Minor Formulation Amendments
h. 98-1 Self Certification of Product Chemistry Data with Attachments (This
document is in PDF format and requires the Acrobat reader.)
Other PR Notices can be found at http://www.epa.gov/opppmsdl/PR_Notices
3. Pesticide Product Registration Application Forms (These forms are in PDF format
and will require the Acrobat reader).
a. EPA Form No. 8570-1, Application for Pesticide Registration/Amendment
b. EPA Form No. 8570-4, Confidential Statement of Formula
c. EPA Form No. 8570-27, Formulator's Exemption Statement
d. EPA Form No. 8570-34, Certification with Respect to Citations of Data
e. EPA Form No. 8570-35, Data Matrix
4. General Pesticide Information (Some of these forms are in PDF format and will
require the Acrobat reader).
a. Registration Division Personnel Contact List
b. Biopesticides and Pollution Prevention Division (BPPD) Contacts
c. Antimicrobials Division Organizational Structure/Contact List
d. 53 F.R. 15952, Pesticide Registration Procedures; Pesticide Data
Requirements (PDF format)
e. 40 CFR Part 156, Labeling Requirements for Pesticides and Devices (PDF
format)
f. 40 CFR Part 158, Data Requirements for Registration (PDF format)
g. 50 F.R. 48833, Disclosure of Reviews of Pesticide Data (November 27, 1985)
Before submitting your application for registration, you may wish to consult some additional
sources of information. These include:
1. The Office of Pesticide Programs' website.
2. The booklet "General Information on Applying for Registration of Pesticides in the
United States", PB92-221811, available through the National Technical Information
Service (NTIS) at the following address:
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161
The telephone number for NTIS is (703) 605-6000.
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3. The National Pesticide Information Retrieval System (NPIRS) of Purdue University's
Center for Environmental and Regulatory Information Systems. This service does
charge a fee for subscriptions and custom searches. You can contact NPIRS by
telephone at (765) 494-6614 or through their website.
4. The National Pesticide Telecommunications Network (NPTN) can provide
information on active ingredients, uses, toxicology, and chemistry of pesticides. You
can contact NPTN by telephone at (800) 858-7378 or through their website:
ace. orst. edu/info/nptn.
The Agency will return a notice of receipt of an application for registration or
amended registration, experimental use permit, or amendment to a petition if the
applicant or petitioner encloses with his submission a stamped, self-addressed
postcard. The postcard must contain the following entries to be completed by OPP:
Date of receipt;
EPA identifying number; and
Product Manager assignment.
Other identifying information may be included by the applicant to link the
acknowledgment of receipt to the specific application submitted. EPA will stamp the
date of receipt and provide the EPA identifying file symbol or petition number for the
new submission. The identifying number should be used whenever you contact the
Agency concerning an application for registration, experimental use permit, or
tolerance petition.
To assist us in ensuring that all data you have submitted for the chemical are properly
coded and assigned to your company, please include a list of all synonyms, common
and trade names, company experimental codes, and other names which identify the
chemical (including "blind" codes used when a sample was submitted for testing by
commercial or academic facilities). Please provide a chemical abstract system (CAS)
number if one has been assigned.
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Documents Associated with this RED
The following documents are part of the Administrative Record for this RED document and
may be included in the EPA's Office of Pesticide Programs Public Docket. Copies of these
documents are not available electronically, but may be obtained by contacting the person listed on
the respective Chemical Status Sheet.
1. Health Effects Division and Environmental Fate and Effects Division Science
Chapters, which include the complete risk assessments and supporting documents.
2. Detailed Label Usage Information System (LUIS) Report.
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